whoops, no ability to add comments in between functions in pseudocode
[openpower-isa.git] / src / openpower / decoder / isa / test_caller_svp64_dct.py
index fa0a71c25988c74cc9b470792284906e34cc0366..ccdae2367cf536ef061c51ce957543c2606f2eda 100644 (file)
@@ -1,7 +1,6 @@
 from nmigen import Module, Signal
 from nmigen.back.pysim import Simulator, Delay, Settle
 from nmutil.formaltest import FHDLTestCase
-import unittest
 from openpower.decoder.power_decoder import (create_pdecode)
 from openpower.simulator.program import Program
 from openpower.decoder.isa.caller import SVP64State
@@ -11,6 +10,236 @@ from openpower.sv.trans.svp64 import SVP64Asm
 from copy import deepcopy
 from openpower.decoder.helpers import fp64toselectable, SINGLE
 from openpower.decoder.isafunctions.double2single import DOUBLE2SINGLE
+from openpower.decoder.isa.remap_dct_yield import (halfrev2, reverse_bits,
+                                         iterate_dct_inner_butterfly_indices,
+                                         iterate_dct_outer_butterfly_indices,
+                                         transform2, inverse_transform2)
+from openpower.decoder.isa.fastdctlee import inverse_transform_iter
+import unittest
+import math
+
+
+def transform_inner_radix2_dct(vec, ctable):
+
+    # Initialization
+    n = len(vec)
+    print ()
+    print ("transform2", n)
+    levels = n.bit_length() - 1
+
+    # reference (read/write) the in-place data in *reverse-bit-order*
+    ri = list(range(n))
+    ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+
+    # and pretend we LDed data in half-swapped *and* bit-reversed order as well
+    # TODO: merge these two
+    vec = halfrev2(vec, False)
+    vec = [vec[ri[i]] for i in range(n)]
+
+    ################
+    # INNER butterfly
+    ################
+    xdim = n
+    ydim = 0
+    zdim = 0
+
+    # set up an SVSHAPE
+    class SVSHAPE:
+        pass
+    # j schedule
+    SVSHAPE0 = SVSHAPE()
+    SVSHAPE0.lims = [xdim, 2, zdim]
+    SVSHAPE0.mode = 0b01
+    SVSHAPE0.submode2 = 0b01
+    SVSHAPE0.skip = 0b00
+    SVSHAPE0.offset = 0       # experiment with different offset, here
+    SVSHAPE0.invxyz = [1,0,0] # inversion if desired
+    # j+halfstep schedule
+    SVSHAPE1 = SVSHAPE()
+    SVSHAPE1.lims = [xdim, 2, zdim]
+    SVSHAPE1.mode = 0b01
+    SVSHAPE1.submode2 = 0b01
+    SVSHAPE1.skip = 0b01
+    SVSHAPE1.offset = 0       # experiment with different offset, here
+    SVSHAPE1.invxyz = [1,0,0] # inversion if desired
+
+    # enumerate over the iterator function, getting new indices
+    i0 = iterate_dct_inner_butterfly_indices(SVSHAPE0)
+    i1 = iterate_dct_inner_butterfly_indices(SVSHAPE1)
+    for k, ((jl, jle), (jh, jhe)) in enumerate(zip(i0, i1)):
+        t1, t2 = vec[jl], vec[jh]
+        coeff = ctable[k]
+        vec[jl] = t1 + t2
+        vec[jh] = (t1 - t2) * (1.0/coeff)
+        print ("coeff", "ci", k,
+                "jl", jl, "jh", jh,
+               "i/n", (k+0.5), 1.0/coeff,
+                "t1, t2", t1, t2, "res", vec[jl], vec[jh],
+                "end", bin(jle), bin(jhe))
+        if jle == 0b111: # all loops end
+            break
+
+    return vec
+
+
+def transform_outer_radix2_dct(vec):
+
+    # Initialization
+    n = len(vec)
+    print ()
+    print ("transform2", n)
+    levels = n.bit_length() - 1
+
+    # outer butterfly
+    xdim = n
+    ydim = 0
+    zdim = 0
+
+    # j schedule
+    class SVSHAPE:
+        pass
+    SVSHAPE0 = SVSHAPE()
+    SVSHAPE0.lims = [xdim, 3, zdim]
+    SVSHAPE0.submode2 = 0b100
+    SVSHAPE0.mode = 0b01
+    SVSHAPE0.skip = 0b00
+    SVSHAPE0.offset = 0       # experiment with different offset, here
+    SVSHAPE0.invxyz = [0,0,0] # inversion if desired
+    # j+halfstep schedule
+    SVSHAPE1 = SVSHAPE()
+    SVSHAPE1.lims = [xdim, 3, zdim]
+    SVSHAPE1.mode = 0b01
+    SVSHAPE1.submode2 = 0b100
+    SVSHAPE1.skip = 0b01
+    SVSHAPE1.offset = 0       # experiment with different offset, here
+    SVSHAPE1.invxyz = [0,0,0] # inversion if desired
+
+    # enumerate over the iterator function, getting new indices
+    i0 = iterate_dct_outer_butterfly_indices(SVSHAPE0)
+    i1 = iterate_dct_outer_butterfly_indices(SVSHAPE1)
+    for k, ((jl, jle), (jh, jhe)) in enumerate(zip(i0, i1)):
+        print ("itersum    jr", jl, jh,
+                "end", bin(jle), bin(jhe))
+        vec[jl] += vec[jh]
+        if jle == 0b111: # all loops end
+            break
+
+    print("transform2 result", vec)
+
+    return vec
+
+
+def transform_inner_radix2_idct(vec, ctable):
+
+    # Initialization
+    n = len(vec)
+    print ()
+    print ("transform2", n)
+    levels = n.bit_length() - 1
+
+    # pretend we LDed data in half-swapped order
+    vec = halfrev2(vec, False)
+
+    ################
+    # INNER butterfly
+    ################
+    xdim = n
+    ydim = 0
+    zdim = 0
+
+    # set up an SVSHAPE
+    class SVSHAPE:
+        pass
+    # j schedule
+    SVSHAPE0 = SVSHAPE()
+    SVSHAPE0.lims = [xdim, 0b000001, 0]
+    SVSHAPE0.mode = 0b11
+    SVSHAPE0.submode2 = 0b11
+    SVSHAPE0.skip = 0b00
+    SVSHAPE0.offset = 0       # experiment with different offset, here
+    SVSHAPE0.invxyz = [0,0,0] # inversion if desired
+    # j+halfstep schedule
+    SVSHAPE1 = SVSHAPE()
+    SVSHAPE1.lims = [xdim, 0b000001, 0]
+    SVSHAPE1.mode = 0b11
+    SVSHAPE1.submode2 = 0b11
+    SVSHAPE1.skip = 0b01
+    SVSHAPE1.offset = 0       # experiment with different offset, here
+    SVSHAPE1.invxyz = [0,0,0] # inversion if desired
+
+    # enumerate over the iterator function, getting new indices
+    i0 = iterate_dct_inner_butterfly_indices(SVSHAPE0)
+    i1 = iterate_dct_inner_butterfly_indices(SVSHAPE1)
+    for k, ((jl, jle), (jh, jhe)) in enumerate(zip(i0, i1)):
+        t1, t2 = vec[jl], vec[jh]
+        coeff = ctable[k]
+        vec[jl] = t1 + t2/coeff
+        vec[jh] = t1 - t2/coeff
+        print ("coeff", "ci", k,
+                "jl", jl, "jh", jh,
+               "i/n", (k+0.5), 1.0/coeff,
+                "t1, t2", t1, t2, "res", vec[jl], vec[jh],
+                "end", bin(jle), bin(jhe))
+        if jle == 0b111: # all loops end
+            break
+
+    return vec
+
+
+def transform_outer_radix2_idct(vec):
+
+    # Initialization
+    n = len(vec)
+    print ()
+    print ("transform2-inv", n)
+    levels = n.bit_length() - 1
+
+    # outer butterfly
+    xdim = n
+    ydim = 0
+    zdim = 0
+
+    # reference (read/write) the in-place data in *reverse-bit-order*
+    ri = list(range(n))
+    ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+
+    # and pretend we LDed data in half-swapped *and* bit-reversed order as well
+    # TODO: merge these two
+    vec = [vec[ri[i]] for i in range(n)]
+    vec = halfrev2(vec, True)
+
+    # j schedule
+    class SVSHAPE:
+        pass
+    SVSHAPE0 = SVSHAPE()
+    SVSHAPE0.lims = [xdim, 2, zdim]
+    SVSHAPE0.submode2 = 0b011
+    SVSHAPE0.mode = 0b11
+    SVSHAPE0.skip = 0b00
+    SVSHAPE0.offset = 0       # experiment with different offset, here
+    SVSHAPE0.invxyz = [1,0,1] # inversion if desired
+    # j+halfstep schedule
+    SVSHAPE1 = SVSHAPE()
+    SVSHAPE1.lims = [xdim, 2, zdim]
+    SVSHAPE1.mode = 0b11
+    SVSHAPE1.submode2 = 0b011
+    SVSHAPE1.skip = 0b01
+    SVSHAPE1.offset = 0       # experiment with different offset, here
+    SVSHAPE1.invxyz = [1,0,1] # inversion if desired
+
+    # enumerate over the iterator function, getting new indices
+    i0 = iterate_dct_outer_butterfly_indices(SVSHAPE0)
+    i1 = iterate_dct_outer_butterfly_indices(SVSHAPE1)
+    for k, ((jl, jle), (jh, jhe)) in enumerate(zip(i0, i1)):
+        print ("itersum    jr", jl, jh,
+                "end", bin(jle), bin(jhe))
+        vec[jh] += vec[jl]
+        if jle == 0b111: # all loops end
+            break
+
+    print("transform2-inv result", vec)
+
+    return vec
 
 
 class DCTTestCase(FHDLTestCase):
@@ -20,7 +249,7 @@ class DCTTestCase(FHDLTestCase):
             self.assertEqual(sim.gpr(i), SelectableInt(expected[i], 64))
 
     def test_sv_ffadds_dct(self):
-        """>>> lst = ["sv.fdmadds 0.v, 8.v, 0.v, 0.v"
+        """>>> lst = ["sv.fdmadds 0.v, 0.v, 0.v, 8.v"
                         ]
             four in-place vector adds, four in-place vector mul-subs
 
@@ -31,26 +260,34 @@ class DCTTestCase(FHDLTestCase):
                 fadds FRT   , FRB, FRA
                 fsubs FRT+vl, FRA, FRB+vl
         """
-        lst = SVP64Asm(["sv.fdmadds 0.v, 8.v, 0.v, 0.v"
+        lst = SVP64Asm(["sv.fdmadds 0.v, 0.v, 0.v, 8.v"
                         ])
         lst = list(lst)
 
+        # cheat here with these values, they're selected so that
+        # rounding errors do not occur. sigh.
         fprs = [0] * 32
-        av = [7.0, -9.8, 2.0, -32.3] # first half of array 0..3
-        bv = [-2.0, 2.0, -9.8, 32.3] # second half of array 4..7
-        cv = [-1.0, 0.5, 2.3, -3.2]  # coefficients
+        av = [7.0, -0.8, 2.0, -2.3] # first half of array 0..3
+        bv = [-2.0, 2.0, -0.8, 1.4] # second half of array 4..7
+        cv = [-1.0, 0.5, 2.5, -0.25]  # coefficients
         res = []
         # work out the results with the twin add-sub
         for i, (a, b, c) in enumerate(zip(av, bv, cv)):
             fprs[i+0] = fp64toselectable(a)
             fprs[i+4] = fp64toselectable(b)
             fprs[i+8] = fp64toselectable(c)
-            t = b + a
-            u = (b - a) * c
-            t = DOUBLE2SINGLE(fp64toselectable(t)) # convert to Power single
-            u = DOUBLE2SINGLE(fp64toselectable(u)) # from double
-            res.append((t, u))
-            print ("FFT", i, "in", a, b, "c", c, "res", t, u)
+            # this isn't quite a perfect replication of the
+            # FP32 mul-add-sub.  better really to use FPMUL32, FPADD32
+            # and FPSUB32 directly to be honest.
+            t = a + b
+            diff = (a - b)
+            diff = DOUBLE2SINGLE(fp64toselectable(diff)) # FP32 round
+            diff = float(diff)
+            u = diff * c
+            tc = DOUBLE2SINGLE(fp64toselectable(t)) # convert to Power single
+            uc = DOUBLE2SINGLE(fp64toselectable(u)) # from double
+            res.append((uc, tc))
+            print ("DCT", i, "in", a, b, "c", c, "res", t, u)
 
         # SVSTATE (in this case, VL=2)
         svstate = SVP64State()
@@ -67,36 +304,48 @@ class DCTTestCase(FHDLTestCase):
                 b = float(sim.fpr(i+4))
                 t = float(t)
                 u = float(u)
-                print ("FFT", i, "in", a, b, "res", t, u)
+                print ("DCT", i, "in", a, b, "res", t, u)
             for i, (t, u) in enumerate(res):
-                self.assertEqual(sim.fpr(i+2), t)
-                self.assertEqual(sim.fpr(i+6), u)
+                self.assertEqual(sim.fpr(i+0), t)
+                self.assertEqual(sim.fpr(i+4), u)
 
-    def tst_sv_remap_fpmadds_dct(self):
+    def test_sv_remap_fpmadds_dct_inner_4(self):
         """>>> lst = ["svshape 4, 1, 1, 2, 0",
-                     "svremap 31, 1, 0, 2, 0, 1, 0",
-                        "sv.ffmadds 0.v, 0.v, 0.v, 8.v"
+                     "svremap 27, 1, 0, 2, 0, 1, 0",
+                        "sv.fdmadds 0.v, 0.v, 0.v, 8.v"
                      ]
-            runs a full in-place O(N log2 N) butterfly schedule for
-            DCT
+            runs a full in-place 4-long O(N log2 N) inner butterfly schedule
+            for DCT
 
             SVP64 "REMAP" in Butterfly Mode is applied to a twin +/- FMAC
             (3 inputs, 2 outputs)
+
+            Note that the coefficient (FRC) is not on a "schedule", it
+            is straight Vectorised (0123...) because DCT coefficients
+            cannot be shared between butterfly layers (due to +0.5)
         """
         lst = SVP64Asm( ["svshape 4, 1, 1, 2, 0",
-                         "svremap 31, 1, 0, 2, 0, 1, 0",
-                        "sv.ffmadds 0.v, 0.v, 0.v, 8.v"
+                         "svremap 27, 1, 0, 2, 0, 1, 0",
+                         "sv.fdmadds 0.v, 0.v, 0.v, 8.v"
                         ])
         lst = list(lst)
 
         # array and coefficients to test
+        n = 4
         av = [7.0, -9.8, 3.0, -32.3]
-        coe = [-0.25, 0.5, 3.1, 6.2, 0.1, -0.2] # 6 coefficients
+        coe = [-0.25, 0.5, 3.1, 6.2] # 4 coefficients
+
+        levels = n.bit_length() - 1
+        ri = list(range(n))
+        ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+        avi = [7.0, -0.8, 2.0, -2.3] # first half of array 0..3
+        av = halfrev2(avi, False)
+        av = [av[ri[i]] for i in range(n)]
 
         # store in regfile
         fprs = [0] * 32
         for i, c in enumerate(coe):
-            fprs[i+8] = fp64toselectable(c)
+            fprs[i+8] = fp64toselectable(1.0 / c) # invert
         for i, a in enumerate(av):
             fprs[i+0] = fp64toselectable(a)
 
@@ -110,10 +359,330 @@ class DCTTestCase(FHDLTestCase):
             print ("spr svshape2", sim.spr['SVSHAPE2'])
             print ("spr svshape3", sim.spr['SVSHAPE3'])
 
-            return
+            # work out the results with the twin mul/add-sub
+            res = transform_inner_radix2_dct(avi, coe)
+
+            for i, expected in enumerate(res):
+                print ("i", i, float(sim.fpr(i)), "expected", expected)
+            for i, expected in enumerate(res):
+                # convert to Power single
+                expected = DOUBLE2SINGLE(fp64toselectable(expected))
+                expected = float(expected)
+                actual = float(sim.fpr(i))
+                # approximate error calculation, good enough test
+                # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
+                # and the rounding is different
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-6)
+
+    def test_sv_remap_fpmadds_idct_inner_4(self):
+        """>>> lst = ["svshape 4, 1, 1, 10, 0",
+                      "svremap 27, 0, 1, 2, 1, 0, 0",
+                      "sv.ffmadds 0.v, 0.v, 0.v, 8.v"
+                     ]
+            runs a full in-place 4-long O(N log2 N) inner butterfly schedule
+            for inverse-DCT
+
+            SVP64 "REMAP" in Butterfly Mode is applied to a twin +/- FMAC
+            (3 inputs, 2 outputs)
+
+            Note that the coefficient (FRC) is not on a "schedule", it
+            is straight Vectorised (0123...) because DCT coefficients
+            cannot be shared between butterfly layers (due to +0.5)
+        """
+        lst = SVP64Asm( ["svshape 4, 1, 1, 10, 0",
+                         "svremap 27, 0, 1, 2, 1, 0, 0",
+                         "sv.ffmadds 0.v, 0.v, 0.v, 8.v"
+                        ])
+        lst = list(lst)
+
+        # array and coefficients to test
+        n = 4
+        levels = n.bit_length() - 1
+        coe = [-0.25, 0.5, 3.1, 6.2] # 4 coefficients
+        avi = [7.0, -0.8, 2.0, -2.3] # first half of array 0..3
+        av = halfrev2(avi, False)
+
+        # store in regfile
+        fprs = [0] * 32
+        for i, c in enumerate(coe):
+            fprs[i+8] = fp64toselectable(1.0 / c) # invert
+        for i, a in enumerate(av):
+            fprs[i+0] = fp64toselectable(a)
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, initial_fprs=fprs)
+            print ("spr svshape0", sim.spr['SVSHAPE0'])
+            print ("    xdimsz", sim.spr['SVSHAPE0'].xdimsz)
+            print ("    ydimsz", sim.spr['SVSHAPE0'].ydimsz)
+            print ("    zdimsz", sim.spr['SVSHAPE0'].zdimsz)
+            print ("spr svshape1", sim.spr['SVSHAPE1'])
+            print ("spr svshape2", sim.spr['SVSHAPE2'])
+            print ("spr svshape3", sim.spr['SVSHAPE3'])
 
             # work out the results with the twin mul/add-sub
-            res = transform_radix2(av, coe)
+            res = transform_inner_radix2_idct(avi, coe)
+
+            for i, expected in enumerate(res):
+                print ("i", i, float(sim.fpr(i)), "expected", expected)
+            for i, expected in enumerate(res):
+                # convert to Power single
+                expected = DOUBLE2SINGLE(fp64toselectable(expected))
+                expected = float(expected)
+                actual = float(sim.fpr(i))
+                # approximate error calculation, good enough test
+                # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
+                # and the rounding is different
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-6)
+
+    def test_sv_remap_fpmadds_idct_outer_8(self):
+        """>>> lst = ["svshape 8, 1, 1, 11, 0",
+                     "svremap 27, 0, 1, 2, 1, 0, 0",
+                         "sv.fadds 0.v, 0.v, 0.v"
+                     ]
+            runs a full in-place 8-long O(N log2 N) outer butterfly schedule
+            for inverse-DCT, does the iterative overlapped ADDs
+
+            SVP64 "REMAP" in Butterfly Mode.
+        """
+        lst = SVP64Asm( ["svshape 8, 1, 1, 11, 0", # outer butterfly
+                         "svremap 27, 0, 1, 2, 1, 0, 0",
+                         "sv.fadds 0.v, 0.v, 0.v"
+                        ])
+        lst = list(lst)
+
+        # array and coefficients to test
+        avi = [7.0, -9.8, 3.0, -32.3, 2.1, 3.6, 0.7, -0.2]
+
+        n = len(avi)
+        levels = n.bit_length() - 1
+        ri = list(range(n))
+        ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+        av = [avi[ri[i]] for i in range(n)]
+        av = halfrev2(av, True)
+
+        # store in regfile
+        fprs = [0] * 32
+        for i, a in enumerate(av):
+            fprs[i+0] = fp64toselectable(a)
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, initial_fprs=fprs)
+            print ("spr svshape0", sim.spr['SVSHAPE0'])
+            print ("    xdimsz", sim.spr['SVSHAPE0'].xdimsz)
+            print ("    ydimsz", sim.spr['SVSHAPE0'].ydimsz)
+            print ("    zdimsz", sim.spr['SVSHAPE0'].zdimsz)
+            print ("spr svshape1", sim.spr['SVSHAPE1'])
+            print ("spr svshape2", sim.spr['SVSHAPE2'])
+            print ("spr svshape3", sim.spr['SVSHAPE3'])
+
+            # outer iterative sum
+            res = transform_outer_radix2_idct(avi)
+
+            for i, expected in enumerate(res):
+                print ("i", i, float(sim.fpr(i)), "expected", expected)
+            for i, expected in enumerate(res):
+                # convert to Power single
+                expected = DOUBLE2SINGLE(fp64toselectable(expected))
+                expected = float(expected)
+                actual = float(sim.fpr(i))
+                # approximate error calculation, good enough test
+                # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
+                # and the rounding is different
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-6)
+
+    def test_sv_remap_fpmadds_dct_outer_8(self):
+        """>>> lst = ["svshape 8, 1, 1, 3, 0",
+                     "svremap 27, 1, 0, 2, 0, 1, 0",
+                         "sv.fadds 0.v, 0.v, 0.v"
+                     ]
+            runs a full in-place 8-long O(N log2 N) outer butterfly schedule
+            for DCT, does the iterative overlapped ADDs
+
+            SVP64 "REMAP" in Butterfly Mode.
+        """
+        lst = SVP64Asm( ["svshape 8, 1, 1, 3, 0",
+                         "svremap 27, 1, 0, 2, 0, 1, 0",
+                         "sv.fadds 0.v, 0.v, 0.v"
+                        ])
+        lst = list(lst)
+
+        # array and coefficients to test
+        av = [7.0, -9.8, 3.0, -32.3, 2.1, 3.6, 0.7, -0.2]
+
+        # store in regfile
+        fprs = [0] * 32
+        for i, a in enumerate(av):
+            fprs[i+0] = fp64toselectable(a)
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, initial_fprs=fprs)
+            print ("spr svshape0", sim.spr['SVSHAPE0'])
+            print ("    xdimsz", sim.spr['SVSHAPE0'].xdimsz)
+            print ("    ydimsz", sim.spr['SVSHAPE0'].ydimsz)
+            print ("    zdimsz", sim.spr['SVSHAPE0'].zdimsz)
+            print ("spr svshape1", sim.spr['SVSHAPE1'])
+            print ("spr svshape2", sim.spr['SVSHAPE2'])
+            print ("spr svshape3", sim.spr['SVSHAPE3'])
+
+            # outer iterative sum
+            res = transform_outer_radix2_dct(av)
+
+            for i, expected in enumerate(res):
+                print ("i", i, float(sim.fpr(i)), "expected", expected)
+            for i, expected in enumerate(res):
+                # convert to Power single
+                expected = DOUBLE2SINGLE(fp64toselectable(expected))
+                expected = float(expected)
+                actual = float(sim.fpr(i))
+                # approximate error calculation, good enough test
+                # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
+                # and the rounding is different
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-6)
+
+    def test_sv_remap_fpmadds_idct_8(self):
+        """>>> lst = ["svremap 27, 1, 0, 2, 0, 1, 1",
+                         "svshape 8, 1, 1, 11, 0",
+                         "sv.fadds 0.v, 0.v, 0.v",
+                         "svshape 8, 1, 1, 10, 0",
+                         "sv.ffmadds 0.v, 0.v, 0.v, 8.v"
+                     ]
+            runs a full in-place 8-long O(N log2 N) inverse-DCT, both
+            inner and outer butterfly "REMAP" schedules.
+        """
+        lst = SVP64Asm( ["svremap 27, 0, 1, 2, 1, 0, 1",
+                         "svshape 8, 1, 1, 11, 0",
+                         "sv.fadds 0.v, 0.v, 0.v",
+                         "svshape 8, 1, 1, 10, 0",
+                         "sv.ffmadds 0.v, 0.v, 0.v, 8.v"
+                        ])
+        lst = list(lst)
+
+        # array and coefficients to test
+        avi = [7.0, -9.8, 3.0, -32.3, 2.1, 3.6, 0.7, -0.2]
+        n = len(avi)
+        levels = n.bit_length() - 1
+        ri = list(range(n))
+        ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+        av = [avi[ri[i]] for i in range(n)]
+        av = halfrev2(av, True)
+
+        # divide first value by 2.0, manually.  rev and halfrev should
+        # not have moved it
+        av[0] /= 2.0
+        #avi[0] /= 2.0
+
+        print ("input data pre idct", av)
+
+        ctable = []
+        size = 2
+        while size <= n:
+            halfsize = size // 2
+            for i in range(n//size):
+                for ci in range(halfsize):
+                    ctable.append(math.cos((ci + 0.5) * math.pi / size) * 2.0)
+            size *= 2
+
+        # store in regfile
+        fprs = [0] * 32
+        for i, a in enumerate(av):
+            fprs[i+0] = fp64toselectable(a)
+        for i, c in enumerate(ctable):
+            fprs[i+8] = fp64toselectable(1.0 / c) # invert
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, initial_fprs=fprs)
+            print ("spr svshape0", sim.spr['SVSHAPE0'])
+            print ("    xdimsz", sim.spr['SVSHAPE0'].xdimsz)
+            print ("    ydimsz", sim.spr['SVSHAPE0'].ydimsz)
+            print ("    zdimsz", sim.spr['SVSHAPE0'].zdimsz)
+            print ("spr svshape1", sim.spr['SVSHAPE1'])
+            print ("spr svshape2", sim.spr['SVSHAPE2'])
+            print ("spr svshape3", sim.spr['SVSHAPE3'])
+
+            # inverse DCT
+            expected = [-15.793373940443367, 27.46969091937703,
+                        -24.712331606496313, 27.03601462756265]
+
+            #res = inverse_transform_iter(avi)
+            res = inverse_transform2(avi)
+            #res = transform_outer_radix2_idct(avi)
+
+            for i, expected in enumerate(res):
+                print ("i", i, float(sim.fpr(i)), "expected", expected)
+            for i, expected in enumerate(res):
+                # convert to Power single
+                expected = DOUBLE2SINGLE(fp64toselectable(expected))
+                expected = float(expected)
+                actual = float(sim.fpr(i))
+                # approximate error calculation, good enough test
+                # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
+                # and the rounding is different
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-5)
+
+    def test_sv_remap_fpmadds_dct_8(self):
+        """>>> lst = ["svremap 27, 1, 0, 2, 0, 1, 1",
+                      "svshape 8, 1, 1, 2, 0",
+                      "sv.fdmadds 0.v, 0.v, 0.v, 8.v"
+                      "svshape 8, 1, 1, 3, 0",
+                      "sv.fadds 0.v, 0.v, 0.v"
+                     ]
+            runs a full in-place 8-long O(N log2 N) DCT, both
+            inner and outer butterfly "REMAP" schedules.
+        """
+        lst = SVP64Asm( ["svremap 27, 1, 0, 2, 0, 1, 1",
+                         "svshape 8, 1, 1, 2, 0",
+                         "sv.fdmadds 0.v, 0.v, 0.v, 8.v",
+                         "svshape 8, 1, 1, 3, 0",
+                         "sv.fadds 0.v, 0.v, 0.v"
+                        ])
+        lst = list(lst)
+
+        # array and coefficients to test
+        avi = [7.0, -9.8, 3.0, -32.3, 2.1, 3.6, 0.7, -0.2]
+        n = len(avi)
+        levels = n.bit_length() - 1
+        ri = list(range(n))
+        ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+        av = halfrev2(avi, False)
+        av = [av[ri[i]] for i in range(n)]
+        ctable = []
+        size = n
+        while size >= 2:
+            halfsize = size // 2
+            for i in range(n//size):
+                for ci in range(halfsize):
+                    ctable.append(math.cos((ci + 0.5) * math.pi / size) * 2.0)
+            size //= 2
+
+        # store in regfile
+        fprs = [0] * 32
+        for i, a in enumerate(av):
+            fprs[i+0] = fp64toselectable(a)
+        for i, c in enumerate(ctable):
+            fprs[i+8] = fp64toselectable(1.0 / c) # invert
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, initial_fprs=fprs)
+            print ("spr svshape0", sim.spr['SVSHAPE0'])
+            print ("    xdimsz", sim.spr['SVSHAPE0'].xdimsz)
+            print ("    ydimsz", sim.spr['SVSHAPE0'].ydimsz)
+            print ("    zdimsz", sim.spr['SVSHAPE0'].zdimsz)
+            print ("spr svshape1", sim.spr['SVSHAPE1'])
+            print ("spr svshape2", sim.spr['SVSHAPE2'])
+            print ("spr svshape3", sim.spr['SVSHAPE3'])
+
+            # outer iterative sum
+            res = transform2(avi)
 
             for i, expected in enumerate(res):
                 print ("i", i, float(sim.fpr(i)), "expected", expected)
@@ -125,8 +694,318 @@ class DCTTestCase(FHDLTestCase):
                 # approximate error calculation, good enough test
                 # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
                 # and the rounding is different
-                err = abs(actual - expected) / expected
-                self.assertTrue(err < 1e-7)
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-5)
+
+    def test_sv_remap_dct_cos_precompute_8(self):
+        """pre-computes a DCT COS table, deliberately using a lot of
+        registers so as to be able to see what is going on (dumping all
+        regs after the run).
+
+        the simpler (scalar) version is in test_caller_transcendentals.py
+        (test_fp_coss_cvt), this is the SVP64 variant.  TODO: really
+        need the new version of fcfids which doesn't spam memory with
+        LD/STs.
+        """
+        lst = SVP64Asm(["svshape 8, 1, 1, 2, 0",
+                        "svremap 0, 0, 0, 2, 0, 1, 1",
+                        "sv.svstep 4.v, 4, 1", # svstep get vector of ci
+                        "sv.svstep 16.v, 3, 1", # svstep get vector of step
+                        "addi 1, 0, 0x0000",
+                        "setvl 0, 0, 12, 0, 1, 1",
+                        "sv.std 4.v, 0(1)",
+                        "sv.lfd  64.v, 0(1)",
+                        "sv.fcfids 48.v, 64.v",
+                        "addi 1, 0, 0x0060",
+                        "sv.std 16.v, 0(1)",
+                        "sv.lfd  12.v, 0(1)",
+                        "sv.fcfids 24.v, 12.v",
+                        "sv.fadds 0.v, 24.v, 43", # plus 0.5
+                        "sv.fmuls 0.v, 0.v, 41", # times PI
+                        "sv.fdivs 0.v, 0.v, 48.v", # div size
+                        "sv.fcoss 80.v, 0.v",
+                        "sv.fdivs 80.v, 43, 80.v", # div 0.5 / x
+                     ])
+        lst = list(lst)
+
+        gprs = [0] * 32
+        fprs = [0] * 128
+        # constants
+        fprs[43] = fp64toselectable(0.5)         # 0.5
+        fprs[41] = fp64toselectable(math.pi) # pi
+        fprs[44] = fp64toselectable(2.0)     # 2.0
+
+        n = 8
+
+        ctable = []
+        size = n
+        while size >= 2:
+            halfsize = size // 2
+            for i in range(n//size):
+                for ci in range(halfsize):
+                    ctable.append(math.cos((ci + 0.5) * math.pi / size) * 2.0)
+            size //= 2
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, gprs, initial_fprs=fprs)
+            print ("MEM")
+            sim.mem.dump()
+            print ("ci FP")
+            for i in range(len(ctable)):
+                actual = float(sim.fpr(i+24))
+                print ("i", i, actual)
+            print ("size FP")
+            for i in range(len(ctable)):
+                actual = float(sim.fpr(i+48))
+                print ("i", i, actual)
+            print ("temps")
+            for i in range(len(ctable)):
+                actual = float(sim.fpr(i))
+                print ("i", i, actual)
+            for i in range(len(ctable)):
+                expected = 1.0/ctable[i]
+                actual = float(sim.fpr(i+80))
+                err = abs((actual - expected) / expected)
+                print ("i", i, actual, "1/expect", 1/expected,
+                                        "expected", expected,
+                                        "err", err)
+                self.assertTrue(err < 1e-6)
+
+    def test_sv_remap_dct_cos_precompute_inner_8(self):
+        """pre-computes a DCT COS table, using the shorter costable
+        indices schedule.  turns out, some COS values are repeated
+        in each layer of the DCT butterfly.
+
+        the simpler (scalar) version is in test_caller_transcendentals.py
+        (test_fp_coss_cvt), this is the SVP64 variant.  TODO: really
+        need the new version of fcfids which doesn't spam memory with
+        LD/STs.
+        """
+        lst = SVP64Asm(["svshape 8, 1, 1, 5, 0",
+                        "svremap 0, 0, 0, 2, 0, 1, 1",
+                        "sv.svstep 4.v, 3, 1", # svstep get vector of ci
+                        "sv.svstep 16.v, 2, 1", # svstep get vector of step
+                        "addi 1, 0, 0x0000",
+                        "setvl 0, 0, 7, 0, 1, 1",
+                        "sv.std 4.v, 0(1)",
+                        "sv.lfd  64.v, 0(1)",
+                        "sv.fcfids 48.v, 64.v",
+                        "addi 1, 0, 0x0060",
+                        "sv.std 16.v, 0(1)",
+                        "sv.lfd  12.v, 0(1)",
+                        "sv.fcfids 24.v, 12.v",
+                        "sv.fadds 0.v, 24.v, 43", # plus 0.5
+                        "sv.fmuls 0.v, 0.v, 41", # times PI
+                        "sv.fdivs 0.v, 0.v, 48.v", # div size
+                        "sv.fcoss 80.v, 0.v",
+                        "sv.fdivs 80.v, 43, 80.v", # div 0.5 / x
+                     ])
+        lst = list(lst)
+
+        gprs = [0] * 32
+        fprs = [0] * 128
+        # constants
+        fprs[43] = fp64toselectable(0.5)         # 0.5
+        fprs[41] = fp64toselectable(math.pi) # pi
+        fprs[44] = fp64toselectable(2.0)     # 2.0
+
+        n = 8
+
+        ctable = []
+        size = n
+        while size >= 2:
+            halfsize = size // 2
+            for ci in range(halfsize):
+                coeff = math.cos((ci + 0.5) * math.pi / size) * 2.0
+                ctable.append(coeff)
+                print ("coeff", "ci", ci, "size", size,
+                   "i/n", (ci+0.5), 1.0/coeff)
+            size //= 2
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, gprs, initial_fprs=fprs)
+            print ("MEM")
+            sim.mem.dump()
+            print ("ci FP")
+            for i in range(len(ctable)):
+                actual = float(sim.fpr(i+24))
+                print ("i", i, actual)
+            print ("size FP")
+            for i in range(len(ctable)):
+                actual = float(sim.fpr(i+48))
+                print ("i", i, actual)
+            print ("temps")
+            for i in range(len(ctable)):
+                actual = float(sim.fpr(i))
+                print ("i", i, actual)
+            for i in range(len(ctable)):
+                expected = 1.0/ctable[i]
+                actual = float(sim.fpr(i+80))
+                err = abs((actual - expected) / expected)
+                print ("i", i, actual, "1/expect", 1/expected,
+                                        "expected", expected,
+                                        "err", err)
+                self.assertTrue(err < 1e-6)
+
+    def test_sv_remap_fpmadds_dct_8_mode_4(self):
+        """>>> lst = ["svremap 31, 1, 0, 2, 0, 1, 1",
+                      "svshape 8, 1, 1, 4, 0",
+                      "sv.fdmadds 0.v, 0.v, 0.v, 8.v"
+                      "svshape 8, 1, 1, 3, 0",
+                      "sv.fadds 0.v, 0.v, 0.v"
+                     ]
+            runs a full in-place 8-long O(N log2 N) DCT, both
+            inner and outer butterfly "REMAP" schedules.
+            uses shorter tables: FRC also needs to be on a Schedule
+        """
+        lst = SVP64Asm( ["svremap 31, 1, 0, 2, 0, 1, 1",
+                         "svshape 8, 1, 1, 4, 0",
+                         "sv.fdmadds 0.v, 0.v, 0.v, 8.v",
+                         "svshape 8, 1, 1, 3, 0",
+                         "sv.fadds 0.v, 0.v, 0.v"
+                        ])
+        lst = list(lst)
+
+        # array and coefficients to test
+        avi = [7.0, -9.8, 3.0, -32.3, 2.1, 3.6, 0.7, -0.2]
+        n = len(avi)
+        levels = n.bit_length() - 1
+        ri = list(range(n))
+        ri = [ri[reverse_bits(i, levels)] for i in range(n)]
+        av = halfrev2(avi, False)
+        av = [av[ri[i]] for i in range(n)]
+        ctable = []
+        size = n
+        while size >= 2:
+            halfsize = size // 2
+            for ci in range(halfsize):
+                ctable.append(math.cos((ci + 0.5) * math.pi / size) * 2.0)
+            size //= 2
+
+        # store in regfile
+        fprs = [0] * 32
+        for i, a in enumerate(av):
+            fprs[i+0] = fp64toselectable(a)
+        for i, c in enumerate(ctable):
+            fprs[i+8] = fp64toselectable(1.0 / c) # invert
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, initial_fprs=fprs)
+            print ("spr svshape0", sim.spr['SVSHAPE0'])
+            print ("    xdimsz", sim.spr['SVSHAPE0'].xdimsz)
+            print ("    ydimsz", sim.spr['SVSHAPE0'].ydimsz)
+            print ("    zdimsz", sim.spr['SVSHAPE0'].zdimsz)
+            print ("spr svshape1", sim.spr['SVSHAPE1'])
+            print ("spr svshape2", sim.spr['SVSHAPE2'])
+            print ("spr svshape3", sim.spr['SVSHAPE3'])
+
+            # outer iterative sum
+            res = transform2(avi)
+
+            for i, expected in enumerate(res):
+                print ("i", i, float(sim.fpr(i)), "expected", expected)
+            for i, expected in enumerate(res):
+                # convert to Power single
+                expected = DOUBLE2SINGLE(fp64toselectable(expected))
+                expected = float(expected)
+                actual = float(sim.fpr(i))
+                # approximate error calculation, good enough test
+                # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
+                # and the rounding is different
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-5)
+
+    def test_sv_remap_fpmadds_ldbrev_dct_8_mode_4(self):
+        """>>> lst = [# LOAD bit-reversed with half-swap
+                      "svshape 8, 1, 1, 6, 0",
+                      "svremap 1, 0, 0, 0, 0, 0, 0, 1",
+                      "sv.lfsbr 0.v, 4(1), 2",
+                      # Inner butterfly, twin +/- MUL-ADD-SUB
+                      "svremap 31, 1, 0, 2, 0, 1, 1",
+                      "svshape 8, 1, 1, 4, 0",
+                      "sv.fdmadds 0.v, 0.v, 0.v, 8.v"
+                      # Outer butterfly, iterative sum
+                      "svshape 8, 1, 1, 3, 0",
+                      "sv.fadds 0.v, 0.v, 0.v"
+                     ]
+            runs a full in-place 8-long O(N log2 N) DCT, both
+            inner and outer butterfly "REMAP" schedules, and using
+            bit-reversed half-swapped LDs.
+            uses shorter pre-loaded COS tables: FRC also needs to be on a
+            Schedule
+        """
+        lst = SVP64Asm( ["addi 1, 0, 0x000",
+                         "svshape 8, 1, 1, 6, 0",
+                         "svremap 1, 0, 0, 0, 0, 0, 0, 1",
+                         "sv.lfsbr 0.v, 4(1), 2",
+                         "svremap 31, 1, 0, 2, 0, 1, 1",
+                         "svshape 8, 1, 1, 4, 0",
+                         "sv.fdmadds 0.v, 0.v, 0.v, 8.v",
+                         "svshape 8, 1, 1, 3, 0",
+                         "sv.fadds 0.v, 0.v, 0.v"
+                        ])
+        lst = list(lst)
+
+        # array and coefficients to test
+        avi = [7.0, -9.8, 3.0, -32.3, 2.1, 3.6, 0.7, -0.2]
+
+        # store in memory, in standard (expected) order, FP32s (2 per 8-bytes)
+        # LD will bring them in, in the correct order.
+        mem = {}
+        val = 0
+        for i, a in enumerate(avi):
+            a = SINGLE(fp64toselectable(a)).value
+            shift = (i % 2) == 1
+            if shift == 0:
+                val = a                         # accumulate for next iteration
+            else:
+                mem[(i//2)*8] = val | (a << 32) # even and odd 4-byte in same 8
+
+        # calculate the (shortened) COS tables, 4 2 1 not 4 2+2 1+1+1+1
+        n = len(avi)
+        ctable = []
+        size = n
+        while size >= 2:
+            halfsize = size // 2
+            for ci in range(halfsize):
+                ctable.append(math.cos((ci + 0.5) * math.pi / size) * 2.0)
+            size //= 2
+
+        # store in regfile
+        fprs = [0] * 32
+        for i, c in enumerate(ctable):
+            fprs[i+8] = fp64toselectable(1.0 / c) # invert
+
+        with Program(lst, bigendian=False) as program:
+            sim = self.run_tst_program(program, initial_fprs=fprs,
+                                                initial_mem=mem)
+            print ("spr svshape0", sim.spr['SVSHAPE0'])
+            print ("    xdimsz", sim.spr['SVSHAPE0'].xdimsz)
+            print ("    ydimsz", sim.spr['SVSHAPE0'].ydimsz)
+            print ("    zdimsz", sim.spr['SVSHAPE0'].zdimsz)
+            print ("spr svshape1", sim.spr['SVSHAPE1'])
+            print ("spr svshape2", sim.spr['SVSHAPE2'])
+            print ("spr svshape3", sim.spr['SVSHAPE3'])
+
+            # outer iterative sum
+            res = transform2(avi)
+
+            for i, expected in enumerate(res):
+                print ("i", i, float(sim.fpr(i)), "expected", expected)
+
+            for i, expected in enumerate(res):
+                # convert to Power single
+                expected = DOUBLE2SINGLE(fp64toselectable(expected))
+                expected = float(expected)
+                actual = float(sim.fpr(i))
+                # approximate error calculation, good enough test
+                # reason: we are comparing FMAC against FMUL-plus-FADD-or-FSUB
+                # and the rounding is different
+                err = abs((actual - expected) / expected)
+                print ("err", i, err)
+                self.assertTrue(err < 1e-5)
 
     def run_tst_program(self, prog, initial_regs=None,
                               svstate=None,