From 56e5a9b4562cebb88ceb6bb6512798327e57468d Mon Sep 17 00:00:00 2001
From: Jacob Lifshay <programmerjake@gmail.com>
Date: Tue, 18 Jul 2023 20:01:30 -0700
Subject: [PATCH] add fminmax tests with corresponding pseudocode fixes

---
 openpower/isa/fptrans.mdwn                    |   6 +-
 .../decoder/isa/test_caller_fminmax.py        |  23 +++
 src/openpower/test/fptrans/fminmax_cases.py   | 179 ++++++++++++++++++
 3 files changed, 205 insertions(+), 3 deletions(-)
 create mode 100644 src/openpower/decoder/isa/test_caller_fminmax.py
 create mode 100644 src/openpower/test/fptrans/fminmax_cases.py

diff --git a/openpower/isa/fptrans.mdwn b/openpower/isa/fptrans.mdwn
index 0a13b3d7..9060c79f 100644
--- a/openpower/isa/fptrans.mdwn
+++ b/openpower/isa/fptrans.mdwn
@@ -1462,9 +1462,9 @@ Pseudo-code:
     b_is_snan <- b_is_nan & (b[12] = 0)
     any_snan <- a_is_snan | b_is_snan
     a_quieted <- a
-    a_quieted[12] = 1
+    a_quieted[12] <- 1
     b_quieted <- b
-    b_quieted[12] = 1
+    b_quieted[12] <- 1
     if a_is_nan | b_is_nan then
         if FMM[2:3] = 0b00 then  # min/maxnum08
             if a_is_snan then result <- a_quieted
@@ -1505,7 +1505,7 @@ Pseudo-code:
         else if cmp_l <u cmp_r then result <- a
         else result <- b
     if any_snan then SetFX(FPSCR.VXSNAN)
-    if (FPSCR.VE = 0) & ¬any_snan then (FRT) <- result
+    if (FPSCR.VE = 0) | ¬any_snan then (FRT) <- result
 
 Special Registers Altered:
 
diff --git a/src/openpower/decoder/isa/test_caller_fminmax.py b/src/openpower/decoder/isa/test_caller_fminmax.py
new file mode 100644
index 00000000..98b9ef2f
--- /dev/null
+++ b/src/openpower/decoder/isa/test_caller_fminmax.py
@@ -0,0 +1,23 @@
+""" fminmax tests
+"""
+
+import unittest
+
+from openpower.test.fptrans.fminmax_cases import FMinMaxCases
+from openpower.test.runner import TestRunnerBase
+
+# writing the test_caller invocation this way makes it work with pytest
+
+
+class TestFMinMax(TestRunnerBase):
+    def __init__(self, test):
+        assert test == 'test'
+        super().__init__(FMinMaxCases().test_data, fp=True)
+
+    def test(self):
+        # dummy function to make unittest try to test this class
+        pass
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/src/openpower/test/fptrans/fminmax_cases.py b/src/openpower/test/fptrans/fminmax_cases.py
new file mode 100644
index 00000000..17e57f91
--- /dev/null
+++ b/src/openpower/test/fptrans/fminmax_cases.py
@@ -0,0 +1,179 @@
+from openpower.test.common import TestAccumulatorBase, skip_case
+from openpower.insndb.asm import SVP64Asm
+from openpower.test.state import ExpectedState
+from openpower.simulator.program import Program
+from openpower.decoder.isa.caller import SVP64State
+from openpower.decoder.power_enums import FMinMaxMode
+from openpower.fpscr import FPSCRState
+import operator
+import struct
+import itertools
+
+
+_TEST_VALUES = [
+    0x0000_0000_0000_0000,  # 0.0
+    0x8000_0000_0000_0000,  # -0.0
+    # too many values, comment some out
+    # 0x0000_0000_0000_0001,  # min denormal
+    # 0x8000_0000_0000_0001,  # - min denormal
+    # 0x0010_0000_0000_0000,  # min normal
+    # 0x8010_0000_0000_0000,  # - min normal
+    # 0x36A0_0000_0000_0000,  # min f32 denormal
+    # 0xB6A0_0000_0000_0000,  # - min f32 denormal
+    # 0x3810_0000_0000_0000,  # min f32 normal
+    # 0xB810_0000_0000_0000,  # - min f32 normal
+    0x3FF0_0000_0000_0000,  # 1.0
+    0xBFF0_0000_0000_0000,  # -1.0
+    0x4000_0000_0000_0000,  # 2.0
+    0xC000_0000_0000_0000,  # -2.0
+    # 0x47EF_FFFF_E000_0000,  # max f32 normal
+    # 0xC7EF_FFFF_E000_0000,  # - max f32 normal
+    # 0x7FEF_FFFF_FFFF_FFFF,  # max normal
+    # 0xFFEF_FFFF_FFFF_FFFF,  # - max normal
+    0x7FF0_0000_0000_0000,  # infinity
+    0xFFF0_0000_0000_0000,  # -infinity
+    # 0x7FF0_0000_0000_0001,  # first sNaN
+    0xFFF0_0000_0000_0001,  # - first sNaN
+    # 0x7FF0_0000_2000_0000,  # first f32 sNaN
+    # 0xFFF0_0000_2000_0000,  # - first f32 sNaN
+    # 0x7FF7_FFFF_E000_0000,  # last f32 sNaN
+    # 0xFFF7_FFFF_E000_0000,  # - last f32 sNaN
+    # 0x7FF7_FFFF_FFFF_FFFF,  # last sNaN
+    # 0xFFF7_FFFF_FFFF_FFFF,  # - last sNaN
+    0x7FF8_0000_0000_0000,  # first qNaN
+    # 0xFFF8_0000_0000_0000,  # - first qNaN
+    # 0x7FFF_FFFF_E000_0000,  # last f32 qNaN
+    # 0xFFFF_FFFF_E000_0000,  # - last f32 qNaN
+    # 0x7FFF_FFFF_FFFF_FFFF,  # last qNaN
+    0xFFFF_FFFF_FFFF_FFFF,  # - last qNaN
+]
+
+
+class FMinMaxCases(TestAccumulatorBase):
+    # _FILTER is for debugging
+    _FILTER = None
+    # _FILTER = {
+    #     'RA': '0x0', 'RB': '0x0',
+    #     'FMM': 'FMinMaxMode.fminnum08', 'VE': False, 'initial_VXSNAN': False,
+    #     'expected': '0x0', 'any_snan': False, 'CR1': 0,
+    # }
+
+    def reference_fminmax(self, FMM, RA, RB):
+        # type: (FMinMaxMode, int, int) -> tuple[int, bool]
+        op = FMinMaxMode(FMM.value & 0b11)
+        is_max = bool(FMM.value & 0b1000)
+        is_mag = bool(FMM.value & 0b100)
+        MANT_MASK = 0xF_FFFF_FFFF_FFFF
+        EXP_MASK = 0x7FF0_0000_0000_0000
+        SIGN_MASK = 0x8000_0000_0000_0000
+        a_is_nan = RA & MANT_MASK and RA & EXP_MASK == EXP_MASK
+        a_quieted = RA | 0x8_0000_0000_0000
+        b_is_nan = RB & MANT_MASK and RB & EXP_MASK == EXP_MASK
+        b_quieted = RB | 0x8_0000_0000_0000
+        a_is_snan = a_is_nan and a_quieted != RA
+        b_is_snan = b_is_nan and b_quieted != RB
+        any_snan = a_is_snan or b_is_snan
+        if op is FMinMaxMode.fminnum08:
+            if a_is_snan:
+                return a_quieted, any_snan
+            if b_is_snan:
+                return b_quieted, any_snan
+            if a_is_nan and b_is_nan:
+                return a_quieted, any_snan
+            if a_is_nan:
+                return RB, any_snan
+            if b_is_nan:
+                return RA, any_snan
+        elif op is FMinMaxMode.fmin19:
+            if a_is_nan:
+                return a_quieted, any_snan
+            if b_is_nan:
+                return b_quieted, any_snan
+        elif op is FMinMaxMode.fminnum19:
+            if a_is_nan and b_is_nan:
+                return a_quieted, any_snan
+            if a_is_nan:
+                return RB, any_snan
+            if b_is_nan:
+                return RA, any_snan
+        else:
+            assert op is FMinMaxMode.fminc
+            if a_is_nan or b_is_nan:
+                return RB, any_snan
+            if RA & ~SIGN_MASK == 0 and RB & ~SIGN_MASK == 0:
+                return RB, any_snan
+        if RA & ~SIGN_MASK == 0 and RB & ~SIGN_MASK == 0:
+            if is_max:
+                return RA & RB, any_snan
+            return RA | RB, any_snan
+        cmp = operator.lt
+        if is_max:
+            cmp = operator.gt
+        cmp_RA = RA
+        cmp_RB = RB
+        if is_mag and RA & ~SIGN_MASK != RB & ~SIGN_MASK:
+            cmp_RA &= ~SIGN_MASK
+            cmp_RB &= ~SIGN_MASK
+        cmp_RA = struct.unpack("<d", struct.pack("<Q", cmp_RA))[0]
+        cmp_RB = struct.unpack("<d", struct.pack("<Q", cmp_RB))[0]
+        if cmp(cmp_RA, cmp_RB):
+            return RA, any_snan
+        return RB, any_snan
+
+    def fminmax(self, FMM, VE, initial_VXSNAN):
+        # type: (FMinMaxMode, bool, bool) -> None
+        if self._FILTER is not None and (
+                str(FMM) != self._FILTER['FMM'] or
+                VE != self._FILTER['VE'] or
+                initial_VXSNAN != self._FILTER['initial_VXSNAN']):
+            return
+        prog = Program(list(SVP64Asm([f"fminmax. 3,4,5,{FMM.value}"])), False)
+        for RA in _TEST_VALUES:
+            for RB in _TEST_VALUES:
+                gprs = [0] * 32
+                fprs = [0] * 32
+                fprs[3] = 0x0123_4567_89AB_CDEF
+                fprs[4] = RA
+                fprs[5] = RB
+                e = ExpectedState(pc=4, int_regs=gprs, fp_regs=fprs)
+                initial_fpscr = FPSCRState()
+                initial_fpscr.VE = VE
+                initial_fpscr.VXSNAN = initial_VXSNAN
+                fpscr = FPSCRState(initial_fpscr)
+                RT, any_snan = self.reference_fminmax(FMM, RA, RB)
+                if any_snan:
+                    if not fpscr.VXSNAN:
+                        fpscr.FX = 1
+                    fpscr.VXSNAN = 1
+                if not fpscr.VE or not any_snan:
+                    e.fpregs[3] = RT
+                else:
+                    e.pc = 0x700
+                    e.sprs['SRR0'] = 0  # insn is at address 0
+                    e.sprs['SRR1'] = e.msr | (1 << (63 - 43))
+                    e.msr = 0x9000000000000001
+                e.fpscr = int(fpscr)
+                cr1 = int(fpscr.FX) << 3
+                cr1 |= int(fpscr.FEX) << 2
+                cr1 |= int(fpscr.VX) << 1
+                cr1 |= int(fpscr.OX)
+                e.crregs[1] = cr1
+                kwargs = dict(
+                    RA=hex(RA), RB=hex(RB), FMM=str(FMM), VE=VE,
+                    initial_VXSNAN=initial_VXSNAN, expected=hex(RT),
+                    any_snan=any_snan, CR1=cr1)
+                if self._FILTER is not None and kwargs != self._FILTER:
+                    continue
+                with self.subTest(**kwargs):
+                    self.add_case(prog, gprs, fpregs=fprs, expected=e,
+                                  initial_fpscr=int(initial_fpscr))
+
+    def case_fminmax(self):
+        for FMM, VE, VXSNAN in itertools.product(
+                FMinMaxMode, (False, True), (False, True)):
+            if VE and VXSNAN:
+                # isn't really a legal state that the simulator can end up in
+                # since MSR.FE0/FE1 are also set, this would have been caught
+                # by whatever previous instruction changed to this state
+                continue
+            self.fminmax(FMM, VE, VXSNAN)
-- 
2.30.2