[Hexagon] Check vector elements for equivalence in the HexagonVectorLoopCarriedReuse...

    If the two instructions being compared for equivalence have corresponding operands
    that are integer constants, then check their values to determine equivalence.

    Patch by Suyog Sarda!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314642 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Hexagon/HexagonVectorLoopCarriedReuse.cpp b/lib/Target/Hexagon/HexagonVectorLoopCarriedReuse.cpp
index aeff5f8..a0fdc70 100644 (file)
--- a/lib/Target/Hexagon/HexagonVectorLoopCarriedReuse.cpp
+++ b/lib/Target/Hexagon/HexagonVectorLoopCarriedReuse.cpp
@@ -340,6 +340,21 @@ bool HexagonVectorLoopCarriedReuse::isEquivalentOperation(Instruction *I1,
         return false;
     }
   }
+
+  // If both the Instructions are of Vector Type and any of the element
+  // is integer constant, check their values too for equivalence.
+  if (I1->getType()->isVectorTy() && I2->getType()->isVectorTy()) {
+    unsigned NumOperands = I1->getNumOperands();
+    for (unsigned i = 0; i < NumOperands; ++i) {
+      ConstantInt *C1 = dyn_cast<ConstantInt>(I1->getOperand(i));
+      ConstantInt *C2 = dyn_cast<ConstantInt>(I2->getOperand(i));
+      if(!C1) continue;
+      assert(C2);
+      if (C1->getSExtValue() != C2->getSExtValue())
+        return false;
+    }
+  }
+
   return true;
 }
 
@@ -520,7 +535,7 @@ bool HexagonVectorLoopCarriedReuse::doVLCR() {
   assert((CurLoop->getNumBlocks() == 1) &&
          "Can do VLCR only on single block loops");
 
-  bool Changed;
+  bool Changed = false;
   bool Continue;
 
   DEBUG(dbgs() << "Working on Loop: " << *CurLoop->getHeader() << "\n");

diff --git a/test/CodeGen/Hexagon/hexagon_vector_loop_carried_reuse_constant.ll b/test/CodeGen/Hexagon/hexagon_vector_loop_carried_reuse_constant.ll
new file mode 100644 (file)
index 0000000..3808364
--- /dev/null
+++ b/test/CodeGen/Hexagon/hexagon_vector_loop_carried_reuse_constant.ll
@@ -0,0 +1,86 @@
+; RUN: opt < %s -hexagon-vlcr -adce -S | FileCheck %s
+
+; CHECK-NOT: %.hexagon.vlcr
+; ModuleID = 'hexagon_vector_loop_carried_reuse.c'
+source_filename = "hexagon_vector_loop_carried_reuse.c"
+target datalayout = "e-m:e-p:32:32:32-a:0-n16:32-i64:64:64-i32:32:32-i16:16:16-i1:8:8-f32:32:32-f64:64:64-v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048"
+target triple = "hexagon"
+
+@W = external local_unnamed_addr global i32, align 4
+
+; Function Attrs: nounwind
+define void @foo(i8* noalias nocapture readonly %src, i8* noalias nocapture %dst, i32 %stride) local_unnamed_addr #0 {
+entry:
+  %add.ptr = getelementptr inbounds i8, i8* %src, i32 %stride
+  %mul = mul nsw i32 %stride, 2
+  %add.ptr1 = getelementptr inbounds i8, i8* %src, i32 %mul
+  %0 = load i32, i32* @W, align 4, !tbaa !1
+  %cmp55 = icmp sgt i32 %0, 0
+  br i1 %cmp55, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  %1 = bitcast i8* %add.ptr1 to <32 x i32>*
+  %2 = load <32 x i32>, <32 x i32>* %1, align 128, !tbaa !5
+  %incdec.ptr4 = getelementptr inbounds i8, i8* %add.ptr1, i32 128
+  %3 = bitcast i8* %incdec.ptr4 to <32 x i32>*
+  %4 = bitcast i8* %add.ptr to <32 x i32>*
+  %5 = load <32 x i32>, <32 x i32>* %4, align 128, !tbaa !5
+  %incdec.ptr2 = getelementptr inbounds i8, i8* %add.ptr, i32 128
+  %6 = bitcast i8* %incdec.ptr2 to <32 x i32>*
+  %7 = bitcast i8* %src to <32 x i32>*
+  %8 = load <32 x i32>, <32 x i32>* %7, align 128, !tbaa !5
+  %incdec.ptr = getelementptr inbounds i8, i8* %src, i32 128
+  %9 = bitcast i8* %incdec.ptr to <32 x i32>*
+  %10 = bitcast i8* %dst to <32 x i32>*
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %out.063 = phi <32 x i32>* [ %10, %for.body.lr.ph ], [ %incdec.ptr18, %for.body ]
+  %p2.062 = phi <32 x i32>* [ %3, %for.body.lr.ph ], [ %incdec.ptr10, %for.body ]
+  %p1.061 = phi <32 x i32>* [ %6, %for.body.lr.ph ], [ %incdec.ptr8, %for.body ]
+  %p0.060 = phi <32 x i32>* [ %9, %for.body.lr.ph ], [ %incdec.ptr6, %for.body ]
+  %i.059 = phi i32 [ 0, %for.body.lr.ph ], [ %add, %for.body ]
+  %a.sroa.0.058 = phi <32 x i32> [ %8, %for.body.lr.ph ], [ %11, %for.body ]
+  %b.sroa.0.057 = phi <32 x i32> [ %5, %for.body.lr.ph ], [ %12, %for.body ]
+  %c.sroa.0.056 = phi <32 x i32> [ %2, %for.body.lr.ph ], [ %13, %for.body ]
+  %incdec.ptr6 = getelementptr inbounds <32 x i32>, <32 x i32>* %p0.060, i32 1
+  %11 = load <32 x i32>, <32 x i32>* %p0.060, align 128, !tbaa !5
+  %incdec.ptr8 = getelementptr inbounds <32 x i32>, <32 x i32>* %p1.061, i32 1
+  %12 = load <32 x i32>, <32 x i32>* %p1.061, align 128, !tbaa !5
+  %incdec.ptr10 = getelementptr inbounds <32 x i32>, <32 x i32>* %p2.062, i32 1
+  %13 = load <32 x i32>, <32 x i32>* %p2.062, align 128, !tbaa !5
+  %14 = tail call <32 x i32> @llvm.hexagon.V6.valignbi.128B(<32 x i32> %a.sroa.0.058, <32 x i32> %b.sroa.0.057, i32 4)
+  %15 = tail call <32 x i32> @llvm.hexagon.V6.vmaxub.128B(<32 x i32> %14, <32 x i32> %c.sroa.0.056)
+  %16 = tail call <32 x i32> @llvm.hexagon.V6.valignbi.128B(<32 x i32> %11, <32 x i32> %12, i32 5)
+  %17 = tail call <32 x i32> @llvm.hexagon.V6.vmaxub.128B(<32 x i32> %16, <32 x i32> %13)
+  %18 = tail call <32 x i32> @llvm.hexagon.V6.valignbi.128B(<32 x i32> %17, <32 x i32> %15, i32 1)
+  %incdec.ptr18 = getelementptr inbounds <32 x i32>, <32 x i32>* %out.063, i32 1
+  store <32 x i32> %18, <32 x i32>* %out.063, align 128, !tbaa !5
+  %add = add nuw nsw i32 %i.059, 128
+  %cmp = icmp slt i32 %add, %0
+  br i1 %cmp, label %for.body, label %for.end.loopexit
+
+for.end.loopexit:                                 ; preds = %for.body
+  br label %for.end
+
+for.end:                                          ; preds = %for.end.loopexit, %entry
+  ret void
+}
+
+; Function Attrs: nounwind readnone
+declare <32 x i32> @llvm.hexagon.V6.vmaxub.128B(<32 x i32>, <32 x i32>) #1
+
+; Function Attrs: nounwind readnone
+declare <32 x i32> @llvm.hexagon.V6.valignbi.128B(<32 x i32>, <32 x i32>, i32) #1
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="hexagonv60" "target-features"="+hvx,+hvx-double,-long-calls" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
+
+!llvm.ident = !{!0}
+
+!0 = !{!"QuIC LLVM Hexagon Clang version hexagon-clang-82-2622 (based on LLVM 5.0.0)"}
+!1 = !{!2, !2, i64 0}
+!2 = !{!"int", !3, i64 0}
+!3 = !{!"omnipotent char", !4, i64 0}
+!4 = !{!"Simple C/C++ TBAA"}
+!5 = !{!3, !3, i64 0}