[llvm] r374851 - Revert [InstCombine] fold a shifted bool zext to a select

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Mon Oct 14 16:55:39 2019
New Revision: 374851

URL: http://llvm.org/viewvc/llvm-project?rev=374851&view=rev
Log:
Revert [InstCombine] fold a shifted bool zext to a select

This reverts r374828 (git commit 1f40f15d54aac06421448b6de131231d2d78bc75) due to bot breakage

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp
    llvm/trunk/test/Transforms/InstCombine/and.ll
    llvm/trunk/test/Transforms/InstCombine/shift.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp?rev=374851&r1=374850&r2=374851&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp Mon Oct 14 16:55:39 2019
@@ -934,12 +934,6 @@ Instruction *InstCombiner::visitShl(Bina
     return BinaryOperator::CreateLShr(
         ConstantInt::get(Ty, APInt::getSignMask(BitWidth)), X);
 
-  // shl (zext (i1 X)), C1 --> select (X, 1 << C1, 0)
-  if (match(Op0, m_ZExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1)) {
-    auto *NewC = ConstantExpr::getShl(ConstantInt::get(Ty, 1), C1);
-    return SelectInst::Create(X, NewC, ConstantInt::getNullValue(Ty));
-  }
-
   return nullptr;
 }
 

Modified: llvm/trunk/test/Transforms/InstCombine/and.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/and.ll?rev=374851&r1=374850&r2=374851&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/and.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/and.ll Mon Oct 14 16:55:39 2019
@@ -346,7 +346,8 @@ define i32 @test30(i1 %X) {
 
 define i32 @test31(i1 %X) {
 ; CHECK-LABEL: @test31(
-; CHECK-NEXT:    [[Z:%.*]] = select i1 [[X:%.*]], i32 16, i32 0
+; CHECK-NEXT:    [[Y:%.*]] = zext i1 %X to i32
+; CHECK-NEXT:    [[Z:%.*]] = shl nuw nsw i32 [[Y]], 4
 ; CHECK-NEXT:    ret i32 [[Z]]
 ;
   %Y = zext i1 %X to i32

Modified: llvm/trunk/test/Transforms/InstCombine/shift.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/shift.ll?rev=374851&r1=374850&r2=374851&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/shift.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/shift.ll Mon Oct 14 16:55:39 2019
@@ -1181,7 +1181,8 @@ define <2 x i65> @test_63(<2 x i64> %t)
 
 define i32 @test_shl_zext_bool(i1 %t) {
 ; CHECK-LABEL: @test_shl_zext_bool(
-; CHECK-NEXT:    [[SHL:%.*]] = select i1 [[T:%.*]], i32 4, i32 0
+; CHECK-NEXT:    [[EXT:%.*]] = zext i1 [[T:%.*]] to i32
+; CHECK-NEXT:    [[SHL:%.*]] = shl nuw nsw i32 [[EXT]], 2
 ; CHECK-NEXT:    ret i32 [[SHL]]
 ;
   %ext = zext i1 %t to i32
@@ -1191,7 +1192,8 @@ define i32 @test_shl_zext_bool(i1 %t) {
 
 define <2 x i32> @test_shl_zext_bool_splat(<2 x i1> %t) {
 ; CHECK-LABEL: @test_shl_zext_bool_splat(
-; CHECK-NEXT:    [[SHL:%.*]] = select <2 x i1> [[T:%.*]], <2 x i32> <i32 8, i32 8>, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[EXT:%.*]] = zext <2 x i1> [[T:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[SHL:%.*]] = shl nuw nsw <2 x i32> [[EXT]], <i32 3, i32 3>
 ; CHECK-NEXT:    ret <2 x i32> [[SHL]]
 ;
   %ext = zext <2 x i1> %t to <2 x i32>
@@ -1201,7 +1203,8 @@ define <2 x i32> @test_shl_zext_bool_spl
 
 define <2 x i32> @test_shl_zext_bool_vec(<2 x i1> %t) {
 ; CHECK-LABEL: @test_shl_zext_bool_vec(
-; CHECK-NEXT:    [[SHL:%.*]] = select <2 x i1> [[T:%.*]], <2 x i32> <i32 4, i32 8>, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[EXT:%.*]] = zext <2 x i1> [[T:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[SHL:%.*]] = shl <2 x i32> [[EXT]], <i32 2, i32 3>
 ; CHECK-NEXT:    ret <2 x i32> [[SHL]]
 ;
   %ext = zext <2 x i1> %t to <2 x i32>