[llvm] e1554ac - Revert "[InstCombine] Remove side effect of replaced constrained intrinsics"
Serge Pavlov via llvm-commits
llvm-commits at lists.llvm.org
Thu May 5 11:09:47 PDT 2022
Author: Serge Pavlov
Date: 2022-05-06T01:09:16+07:00
New Revision: e1554ac63a903891843b248d611fa8e9fc75d476
URL: https://github.com/llvm/llvm-project/commit/e1554ac63a903891843b248d611fa8e9fc75d476
DIFF: https://github.com/llvm/llvm-project/commit/e1554ac63a903891843b248d611fa8e9fc75d476.diff
LOG: Revert "[InstCombine] Remove side effect of replaced constrained intrinsics"
This reverts commit 83914ee96fc2d828e1cfb8913f5d156d39150e2c.
The change caused discussion: https://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20220502/1034841.html
Added:
Modified:
llvm/include/llvm/Analysis/InstructionSimplify.h
llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
Removed:
llvm/test/Transforms/InstCombine/constrained.ll
################################################################################
diff --git a/llvm/include/llvm/Analysis/InstructionSimplify.h b/llvm/include/llvm/Analysis/InstructionSimplify.h
index 612a73551f7201..8f6ed3a6a19284 100644
--- a/llvm/include/llvm/Analysis/InstructionSimplify.h
+++ b/llvm/include/llvm/Analysis/InstructionSimplify.h
@@ -299,10 +299,6 @@ Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, FastMathFlags FMF,
const SimplifyQuery &Q);
/// Given a callsite, fold the result or return null.
-///
-/// \note A call with declared side effect may be simplified into a value
-/// without such. It happens if simplification code deduces that side effect
-/// is actually absent.
Value *SimplifyCall(CallBase *Call, const SimplifyQuery &Q);
/// Given an operand for a Freeze, see if we can fold the result.
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 6b2ab24b4b746c..c96919caee2b1a 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1237,16 +1237,6 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
return NewCall;
}
- // Unused constrained FP intrinsic calls may have declared side effect, which
- // actually absent. If SimplifyCall returns a replacement for such call,
- // assume side effect is absent and the call may be removed.
- if (CI.use_empty() && isa<ConstrainedFPIntrinsic>(CI)) {
- if (SimplifyCall(&CI, SQ.getWithInstruction(&CI))) {
- eraseInstFromFunction(CI);
- return nullptr;
- }
- }
-
Intrinsic::ID IID = II->getIntrinsicID();
switch (IID) {
case Intrinsic::objectsize:
diff --git a/llvm/test/Transforms/InstCombine/constrained.ll b/llvm/test/Transforms/InstCombine/constrained.ll
deleted file mode 100644
index b5ef71e6edfba5..00000000000000
--- a/llvm/test/Transforms/InstCombine/constrained.ll
+++ /dev/null
@@ -1,125 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -instcombine %s | FileCheck %s
-
-; Treatment of operation with unused result.
-
-; If operation does not raise exceptions, it may be removed even in strict mode.
-define float @f_unused_precise() #0 {
-; CHECK-LABEL: @f_unused_precise(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret float 1.000000e+00
-;
-entry:
- %result = call float @llvm.experimental.constrained.fadd.f32(float 1.0, float 1.0, metadata !"round.upward", metadata !"fpexcept.strict") #0
- ret float 1.0
-}
-
-; If operation raises exceptions, it cannot be removed in strict mode.
-define float @f_unused_strict() #0 {
-; CHECK-LABEL: @f_unused_strict(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: [[RESULT:%.*]] = call float @llvm.experimental.constrained.fdiv.f32(float 1.000000e+00, float 3.000000e+00, metadata !"round.tonearest", metadata !"fpexcept.strict") #[[ATTR0:[0-9]+]]
-; CHECK-NEXT: ret float 1.000000e+00
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.tonearest", metadata !"fpexcept.strict") #0
- ret float 1.0
-}
-
-; If operation raises exceptions, it can be removed in non-strict mode.
-define float @f_unused_ignore() #0 {
-; CHECK-LABEL: @f_unused_ignore(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret float 1.000000e+00
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.towardzero", metadata !"fpexcept.ignore") #0
- ret float 1.0
-}
-
-; If operation raises exceptions, it can be removed in non-strict mode even if rounding mode is dynamic.
-define float @f_unused_dynamic_ignore() #0 {
-; CHECK-LABEL: @f_unused_dynamic_ignore(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret float 1.000000e+00
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.dynamic", metadata !"fpexcept.ignore") #0
- ret float 1.0
-}
-
-; If operation raises exceptions, it can be removed in "maytrap" mode.
-define float @f_unused_maytrap() #0 {
-; CHECK-LABEL: @f_unused_maytrap(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret float 1.000000e+00
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.tonearest", metadata !"fpexcept.maytrap") #0
- ret float 1.0
-}
-
-; Constant evaluation.
-
-; If operation does not raise exceptions, it may be folded even in strict mode.
-define float @f_eval_precise() #0 {
-; CHECK-LABEL: @f_eval_precise(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret float 2.000000e+00
-;
-entry:
- %result = call float @llvm.experimental.constrained.fadd.f32(float 1.0, float 1.0, metadata !"round.upward", metadata !"fpexcept.strict") #0
- ret float %result
-}
-
-; If operation raises exceptions, it cannot be folded in strict mode.
-define float @f_eval_strict() #0 {
-; CHECK-LABEL: @f_eval_strict(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: [[RESULT:%.*]] = call float @llvm.experimental.constrained.fdiv.f32(float 1.000000e+00, float 3.000000e+00, metadata !"round.upward", metadata !"fpexcept.strict") #[[ATTR0]]
-; CHECK-NEXT: ret float [[RESULT]]
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.upward", metadata !"fpexcept.strict") #0
- ret float %result
-}
-
-; If operation raises exceptions, it can be folded in non-strict mode.
-define float @f_eval_ignore() #0 {
-; CHECK-LABEL: @f_eval_ignore(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret float 0x3FD5555540000000
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.downward", metadata !"fpexcept.ignore") #0
- ret float %result
-}
-
-; if result is imprecise, it cannot be folded if rounding mode is dynamic.
-define float @f_eval_dynamic_ignore() #0 {
-; CHECK-LABEL: @f_eval_dynamic_ignore(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: [[RESULT:%.*]] = call float @llvm.experimental.constrained.fdiv.f32(float 1.000000e+00, float 3.000000e+00, metadata !"round.dynamic", metadata !"fpexcept.ignore") #[[ATTR0]]
-; CHECK-NEXT: ret float [[RESULT]]
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.dynamic", metadata !"fpexcept.ignore") #0
- ret float %result
-}
-
-; If result is imprecise and rounding mode is not dynamic, operation can be folded in "maytrap" mode.
-define float @f_eval_maytrap() #0 {
-; CHECK-LABEL: @f_eval_maytrap(
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret float 0x3FD5555560000000
-;
-entry:
- %result = call float @llvm.experimental.constrained.fdiv.f32(float 1.0, float 3.0, metadata !"round.tonearest", metadata !"fpexcept.maytrap") #0
- ret float %result
-}
-
-
-declare float @llvm.experimental.constrained.fadd.f32(float, float, metadata, metadata)
-declare float @llvm.experimental.constrained.fdiv.f32(float, float, metadata, metadata)
-
-attributes #0 = { strictfp }
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