[llvm] r304668 - [ConstantFolding] Fix constant folding for vector cttz and ctlz intrinsics to understand that the second argument is still a scalar.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Sat Jun  3 13:50:29 2017
New Revision: 304668

URL: http://llvm.org/viewvc/llvm-project?rev=304668&view=rev
Log:
[ConstantFolding] Fix constant folding for vector cttz and ctlz intrinsics to understand that the second argument is still a scalar.

Modified:
    llvm/trunk/lib/Analysis/ConstantFolding.cpp
    llvm/trunk/test/Transforms/InstCombine/intrinsics.ll
    llvm/trunk/test/Transforms/InstSimplify/call.ll

Modified: llvm/trunk/lib/Analysis/ConstantFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ConstantFolding.cpp?rev=304668&r1=304667&r2=304668&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ConstantFolding.cpp (original)
+++ llvm/trunk/lib/Analysis/ConstantFolding.cpp Sat Jun  3 13:50:29 2017
@@ -2034,6 +2034,13 @@ Constant *ConstantFoldVectorCall(StringR
   for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
     // Gather a column of constants.
     for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) {
+      // These intrinsics use a scalar type for their second argument.
+      if (J == 1 &&
+          (IntrinsicID == Intrinsic::cttz || IntrinsicID == Intrinsic::ctlz)) {
+        Lane[J] = Operands[J];
+        continue;
+      }
+
       Constant *Agg = Operands[J]->getAggregateElement(I);
       if (!Agg)
         return nullptr;

Modified: llvm/trunk/test/Transforms/InstCombine/intrinsics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/intrinsics.ll?rev=304668&r1=304667&r2=304668&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/intrinsics.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/intrinsics.ll Sat Jun  3 13:50:29 2017
@@ -537,8 +537,7 @@ define i32 @ctlz_undef(i32 %Value) {
 
 define <2 x i32> @ctlz_undef_vec(<2 x i32> %Value) {
 ; CHECK-LABEL: @ctlz_undef_vec(
-; CHECK-NEXT:    [[CTLZ:%.*]] = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> zeroinitializer, i1 true)
-; CHECK-NEXT:    ret <2 x i32> [[CTLZ]]
+; CHECK-NEXT:    ret <2 x i32> undef
 ;
   %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> zeroinitializer, i1 true)
   ret <2 x i32> %ctlz
@@ -575,8 +574,7 @@ define i32 @cttz_undef(i32 %Value) nounw
 
 define <2 x i32> @cttz_undef_vec(<2 x i32> %Value) nounwind {
 ; CHECK-LABEL: @cttz_undef_vec(
-; CHECK-NEXT:    [[CTTZ:%.*]] = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> zeroinitializer, i1 true)
-; CHECK-NEXT:    ret <2 x i32> [[CTTZ]]
+; CHECK-NEXT:    ret <2 x i32> undef
 ;
   %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> zeroinitializer, i1 true)
   ret <2 x i32> %cttz

Modified: llvm/trunk/test/Transforms/InstSimplify/call.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/call.ll?rev=304668&r1=304667&r2=304668&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/call.ll (original)
+++ llvm/trunk/test/Transforms/InstSimplify/call.ll Sat Jun  3 13:50:29 2017
@@ -203,8 +203,7 @@ declare <2 x i256> @llvm.cttz.v2i256(<2
 
 define <2 x i256> @test_cttz_vec() {
 ; CHECK-LABEL: @test_cttz_vec(
-; CHECK-NEXT:    [[X:%.*]] = call <2 x i256> @llvm.cttz.v2i256(<2 x i256> <i256 10, i256 10>, i1 false)
-; CHECK-NEXT:    ret <2 x i256> [[X]]
+; CHECK-NEXT:    ret <2 x i256> <i256 1, i256 1>
 ;
   %x = call <2 x i256> @llvm.cttz.v2i256(<2 x i256> <i256 10, i256 10>, i1 false)
   ret <2 x i256> %x