From: Craig Topper <craig.topper@gmail.com>
Date: Sat, 3 Jun 2017 18:50:29 +0000 (+0000)
Subject: [ConstantFolding] Fix constant folding for vector cttz and ctlz intrinsics to underst... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=02c1af0c1534d11bab661cedb3af9e443b8075c6;p=llvm

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304668 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index a906770dbb3..d33fe4a0094 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -2034,6 +2034,13 @@ Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
   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;
diff --git a/test/Transforms/InstCombine/intrinsics.ll b/test/Transforms/InstCombine/intrinsics.ll
index 04b9088e362..abe0c784754 100644
--- a/test/Transforms/InstCombine/intrinsics.ll
+++ b/test/Transforms/InstCombine/intrinsics.ll
@@ -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) nounwind {
 
 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
diff --git a/test/Transforms/InstSimplify/call.ll b/test/Transforms/InstSimplify/call.ll
index ee8f35aa7cd..994ff6b8c0d 100644
--- a/test/Transforms/InstSimplify/call.ll
+++ b/test/Transforms/InstSimplify/call.ll
@@ -203,8 +203,7 @@ declare <2 x i256> @llvm.cttz.v2i256(<2 x i256> %src, i1 %is_zero_undef)
 
 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