From: Jordi Vaquero <jordi.vaquero@metempsy.com>
Date: Fri, 17 Apr 2020 14:00:13 +0000 (+0200)
Subject: arch-arm: Fix SVE indx inst by sizeof error and dest overwrite
X-Git-Tag: v20.1.0.0~654
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=3eab6ea51e4c2b97e7a68835dddacb989d7559c4;p=gem5.git

arch-arm: Fix SVE indx inst by sizeof error and dest overwrite

This patch includes two fixes for SVE FMUL; FMLA FMLS AND FCMLA instructions

+ Fixes indexed functions like FMUL, FMLA, FMLS, FCMLA due to its
destination register overwrite with temporary values, wince the imm
can make changes in vector positions that will be read in the future.

+ sizeof return bytes not bits so division of 128 shouild be of 16 instead

Change-Id: I304d1b254a299069c85bbc3319e5a6d4119436d0
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28228
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---

diff --git a/src/arch/arm/isa/insts/sve.isa b/src/arch/arm/isa/insts/sve.isa
index 16597d6d6..9314ba9a6 100644
--- a/src/arch/arm/isa/insts/sve.isa
+++ b/src/arch/arm/isa/insts/sve.isa
@@ -1835,26 +1835,25 @@ let {{
                 xc->tcBase());
 
         // Number of elements in a 128 bit segment
-        constexpr unsigned ePerSegment = 128 / sizeof(Element);
+        constexpr unsigned ePerSegment = 16 / sizeof(Element);
 
-        '''
-
-        code += '''
+        ArmISA::VecRegContainer tmpC;
+        auto auxDest = tmpC.as<TPElem>();
         for (unsigned i = 0; i < eCount; i++) {
-                const auto segmentBase = i - i % ePerSegment;
-                const auto segmentIdx = segmentBase + index;
-
-                const Element& srcElem1 = AA64FpOp1_x[i];
-                const Element& srcElem2 = AA64FpOp2_x[segmentIdx];
-                Element destElem = 0;
+            const auto segmentBase = i - i %% ePerSegment;
+            const auto segmentIdx = segmentBase + index;
 
-        '''
+            const Element& srcElem1 = AA64FpOp1_x[i];
+            const Element& srcElem2 = AA64FpOp2_x[segmentIdx];
+            Element destElem = 0;
 
-        code += '''
-        %(op)s
-        AA64FpDest_x[i] = destElem;
+            %(op)s
+            auxDest[i] = destElem;
         }
-        ''' % {'op': op}
+
+        for (unsigned i = 0; i < eCount; i++) {
+            AA64FpDest_x[i] = auxDest[i];
+        }''' % {'op':op}
 
         baseClass = 'SveBinIdxUnpredOp'
 
@@ -2067,8 +2066,10 @@ let {{
                 xc->tcBase());
 
         // Number of elements in a 128 bit segment
-        constexpr unsigned ePerSegment = 128 / sizeof(Element);
+        constexpr unsigned ePerSegment = 16 / sizeof(Element);
 
+        ArmISA::VecRegContainer tmpC;
+        auto auxDest = tmpC.as<TPElem>();
         for (unsigned i = 0; i < eCount; i++) {
             const auto segmentBase = i - i % ePerSegment;
             const auto segmentIdx = segmentBase + index;
@@ -2077,10 +2078,13 @@ let {{
             const Element& srcElem2 = AA64FpOp2_x[segmentIdx];
             Element destElem = AA64FpDestMerge_x[i];
         '''
-
         code += '''
             %(op)s
-            AA64FpDest_x[i] = destElem;
+            auxDest[i] = destElem;
+        }
+
+        for (unsigned i = 0; i < eCount; i++) {
+            AA64FpDest_x[i] = auxDest[i];
         }''' % {'op': op}
 
         iop = InstObjParams(name, 'Sve' + Name, 'SveBinIdxUnpredOp',
@@ -3024,6 +3028,9 @@ let {{
             code += '''
         uint32_t eltspersegment = 16 / (2 * sizeof(Element));'''
         code += '''
+        ArmISA::VecRegContainer tmpC;
+        auto auxDest = tmpC.as<TPElem>();
+
         for (int i = 0; i < eCount / 2; ++i) {'''
         if predType == PredType.NONE:
             code += '''
@@ -3067,9 +3074,14 @@ let {{
             code += '''
             }'''
         code += '''
-            AA64FpDest_x[2 * i] = addend_r;
-            AA64FpDest_x[2 * i + 1] = addend_i;
-        }'''
+            auxDest[2 * i] = addend_r;
+            auxDest[2 * i + 1] = addend_i;
+        }
+
+        for (unsigned i = 0; i < eCount; i++) {
+            AA64FpDest_x[i] = auxDest[i];
+        }
+        '''
         iop = InstObjParams(name, 'Sve' + Name,
                 'SveComplexIdxOp' if predType == PredType.NONE
                                   else 'SveComplexOp',