[llvm] ea7f17e - [InstCombine] Simplify calls with casted `returned` attribute
Johannes Doerfert via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 15 22:57:47 PDT 2020
Author: Johannes Doerfert
Date: 2020-04-16T00:56:00-05:00
New Revision: ea7f17ee387062fcb74af2ba27c426a68c6bc8ad
URL: https://github.com/llvm/llvm-project/commit/ea7f17ee387062fcb74af2ba27c426a68c6bc8ad
DIFF: https://github.com/llvm/llvm-project/commit/ea7f17ee387062fcb74af2ba27c426a68c6bc8ad.diff
LOG: [InstCombine] Simplify calls with casted `returned` attribute
The handling of the `returned` attribute in D75815 did miss the case
where the argument is (bit)casted to a different type. This is
explicitly allowed by the language reference and exposed by the
Attributor.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D77977
Added:
Modified:
llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
llvm/test/Transforms/InstCombine/call-returned.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 28236ad4933d..26fe9e659c7e 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -4654,8 +4654,13 @@ Instruction *InstCombiner::visitCallBase(CallBase &Call) {
}
if (!Call.use_empty() && !Call.isMustTailCall())
- if (Value *ReturnedArg = Call.getReturnedArgOperand())
- return replaceInstUsesWith(Call, ReturnedArg);
+ if (Value *ReturnedArg = Call.getReturnedArgOperand()) {
+ Type *CallTy = Call.getType();
+ Type *RetArgTy = ReturnedArg->getType();
+ if (RetArgTy->canLosslesslyBitCastTo(CallTy))
+ return replaceInstUsesWith(
+ Call, Builder.CreateBitOrPointerCast(ReturnedArg, CallTy));
+ }
if (isAllocLikeFn(&Call, &TLI))
return visitAllocSite(Call);
diff --git a/llvm/test/Transforms/InstCombine/call-returned.ll b/llvm/test/Transforms/InstCombine/call-returned.ll
index 24d95a316c42..bf442b0e9679 100644
--- a/llvm/test/Transforms/InstCombine/call-returned.ll
+++ b/llvm/test/Transforms/InstCombine/call-returned.ll
@@ -3,6 +3,8 @@
declare i32 @passthru_i32(i32 returned)
declare i8* @passthru_p8(i8* returned)
+declare i8* @passthru_p8_from_p32(i32* returned)
+declare <8 x i8> @passthru_8i8v_from_2i32v(<2 x i32> returned)
define i32 @returned_const_int_arg() {
; CHECK-LABEL: @returned_const_int_arg(
@@ -22,6 +24,46 @@ define i8* @returned_const_ptr_arg() {
ret i8* %x
}
+define i8* @returned_const_ptr_arg_casted() {
+; CHECK-LABEL: @returned_const_ptr_arg_casted(
+; CHECK-NEXT: [[X:%.*]] = call i8* @passthru_p8_from_p32(i32* null)
+; CHECK-NEXT: ret i8* null
+;
+ %x = call i8* @passthru_p8_from_p32(i32* null)
+ ret i8* %x
+}
+
+define i8* @returned_ptr_arg_casted(i32* %a) {
+; CHECK-LABEL: @returned_ptr_arg_casted(
+; CHECK-NEXT: [[TMP1:%.*]] = bitcast i32* [[A:%.*]] to i8*
+; CHECK-NEXT: [[X:%.*]] = call i8* @passthru_p8_from_p32(i32* [[A]])
+; CHECK-NEXT: ret i8* [[TMP1]]
+;
+ %x = call i8* @passthru_p8_from_p32(i32* %a)
+ ret i8* %x
+}
+
+ at GV = constant <2 x i32> zeroinitializer
+define <8 x i8> @returned_const_vec_arg_casted() {
+; CHECK-LABEL: @returned_const_vec_arg_casted(
+; CHECK-NEXT: [[X:%.*]] = call <8 x i8> @passthru_8i8v_from_2i32v(<2 x i32> zeroinitializer)
+; CHECK-NEXT: ret <8 x i8> zeroinitializer
+;
+ %v = load <2 x i32>, <2 x i32>* @GV
+ %x = call <8 x i8> @passthru_8i8v_from_2i32v(<2 x i32> %v)
+ ret <8 x i8> %x
+}
+
+define <8 x i8> @returned_vec_arg_casted(<2 x i32> %a) {
+; CHECK-LABEL: @returned_vec_arg_casted(
+; CHECK-NEXT: [[TMP1:%.*]] = bitcast <2 x i32> [[A:%.*]] to <8 x i8>
+; CHECK-NEXT: [[X:%.*]] = call <8 x i8> @passthru_8i8v_from_2i32v(<2 x i32> [[A]])
+; CHECK-NEXT: ret <8 x i8> [[TMP1]]
+;
+ %x = call <8 x i8> @passthru_8i8v_from_2i32v(<2 x i32> %a)
+ ret <8 x i8> %x
+}
+
define i32 @returned_var_arg(i32 %arg) {
; CHECK-LABEL: @returned_var_arg(
; CHECK-NEXT: [[X:%.*]] = call i32 @passthru_i32(i32 [[ARG:%.*]])
@@ -48,3 +90,4 @@ define i32 @returned_var_arg_musttail(i32 %arg) {
%x = musttail call i32 @passthru_i32(i32 %arg)
ret i32 %x
}
+
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