diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCasts.cpp | 13 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/trunc.ll | 13 |
2 files changed, 11 insertions, 15 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index fa24800717..555b4428d2 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -648,10 +648,8 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) { if (!I) return false; // If the input is a truncate from the destination type, we can trivially - // eliminate it, even if it has multiple uses. - // FIXME: This is currently disabled until codegen can handle this without - // pessimizing code, PR5997. - if (0 && isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty) + // eliminate it. + if (isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty) return true; // We can't extend or shrink something that has multiple uses: doing so would @@ -992,11 +990,8 @@ static bool CanEvaluateSExtd(Value *V, Type *Ty) { Instruction *I = dyn_cast<Instruction>(V); if (!I) return false; - // If this is a truncate from the dest type, we can trivially eliminate it, - // even if it has multiple uses. - // FIXME: This is currently disabled until codegen can handle this without - // pessimizing code, PR5997. - if (0 && isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty) + // If this is a truncate from the dest type, we can trivially eliminate it. + if (isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty) return true; // We can't extend or shrink something that has multiple uses: doing so would diff --git a/test/Transforms/InstCombine/trunc.ll b/test/Transforms/InstCombine/trunc.ll index 6ec342a4f5..cbbad7f797 100644 --- a/test/Transforms/InstCombine/trunc.ll +++ b/test/Transforms/InstCombine/trunc.ll @@ -12,8 +12,8 @@ define i64 @test1(i64 %a) { call void @use(i32 %b) ret i64 %d ; CHECK: @test1 -; CHECK: %d = and i64 %a, 15 -; CHECK: ret i64 %d +; CHECK-NOT: ext +; CHECK: ret } define i64 @test2(i64 %a) { %b = trunc i64 %a to i32 @@ -34,8 +34,8 @@ define i64 @test3(i64 %a) { call void @use(i32 %b) ret i64 %d ; CHECK: @test3 -; CHECK: %d = and i64 %a, 8 -; CHECK: ret i64 %d +; CHECK-NOT: ext +; CHECK: ret } define i64 @test4(i64 %a) { %b = trunc i64 %a to i32 @@ -46,8 +46,9 @@ define i64 @test4(i64 %a) { ret i64 %d ; CHECK: @test4 ; CHECK: = and i64 %a, 8 -; CHECK: %d = xor i64 {{.*}}, 8 -; CHECK: ret i64 %d +; CHECK: = xor i64 {{.*}}, 8 +; CHECK-NOT: ext +; CHECK: ret } define i32 @test5(i32 %A) { |