[llvm] r321710 - [InstSimplify] Missed optimization in math expression: squashing exp(log), log(exp)
Dmitry Venikov via llvm-commits
llvm-commits at lists.llvm.org
Wed Jan 3 06:37:42 PST 2018
Author: quolyk
Date: Wed Jan 3 06:37:42 2018
New Revision: 321710
URL: http://llvm.org/viewvc/llvm-project?rev=321710&view=rev
Log:
[InstSimplify] Missed optimization in math expression: squashing exp(log), log(exp)
Summary: This patch enables folding following expressions under -ffast-math flag: exp(log(x)) -> x, exp2(log2(x)) -> x, log(exp(x)) -> x, log2(exp2(x)) -> x
Reviewers: spatel, hfinkel, davide
Reviewed By: spatel, hfinkel, davide
Subscribers: scanon, llvm-commits
Differential Revision: https://reviews.llvm.org/D41381
Added:
llvm/trunk/test/Transforms/InstSimplify/exp-intrinsic.ll
llvm/trunk/test/Transforms/InstSimplify/exp2-intrinsic.ll
llvm/trunk/test/Transforms/InstSimplify/log-intrinsic.ll
llvm/trunk/test/Transforms/InstSimplify/log2-intrinsic.ll
Modified:
llvm/trunk/lib/Analysis/InstructionSimplify.cpp
Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=321710&r1=321709&r2=321710&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Wed Jan 3 06:37:42 2018
@@ -4493,28 +4493,55 @@ static Value *SimplifyIntrinsic(Function
}
}
+ Value *IIOperand = *ArgBegin;
+ Value *X;
switch (IID) {
case Intrinsic::fabs: {
- if (SignBitMustBeZero(*ArgBegin, Q.TLI))
- return *ArgBegin;
+ if (SignBitMustBeZero(IIOperand, Q.TLI))
+ return IIOperand;
return nullptr;
}
case Intrinsic::bswap: {
- Value *IIOperand = *ArgBegin;
- Value *X = nullptr;
// bswap(bswap(x)) -> x
if (match(IIOperand, m_BSwap(m_Value(X))))
return X;
return nullptr;
}
case Intrinsic::bitreverse: {
- Value *IIOperand = *ArgBegin;
- Value *X = nullptr;
// bitreverse(bitreverse(x)) -> x
if (match(IIOperand, m_BitReverse(m_Value(X))))
return X;
return nullptr;
}
+ case Intrinsic::exp: {
+ // exp(log(x)) -> x
+ if (Q.CxtI->isFast() &&
+ match(IIOperand, m_Intrinsic<Intrinsic::log>(m_Value(X))))
+ return X;
+ return nullptr;
+ }
+ case Intrinsic::exp2: {
+ // exp2(log2(x)) -> x
+ if (Q.CxtI->isFast() &&
+ match(IIOperand, m_Intrinsic<Intrinsic::log2>(m_Value(X))))
+ return X;
+ return nullptr;
+ }
+ case Intrinsic::log: {
+ // log(exp(x)) -> x
+ if (Q.CxtI->isFast() &&
+ match(IIOperand, m_Intrinsic<Intrinsic::exp>(m_Value(X))))
+ return X;
+ return nullptr;
+ }
+ case Intrinsic::log2: {
+ // log2(exp2(x)) -> x
+ if (Q.CxtI->isFast() &&
+ match(IIOperand, m_Intrinsic<Intrinsic::exp2>(m_Value(X)))) {
+ return X;
+ }
+ return nullptr;
+ }
default:
return nullptr;
}
Added: llvm/trunk/test/Transforms/InstSimplify/exp-intrinsic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/exp-intrinsic.ll?rev=321710&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/exp-intrinsic.ll (added)
+++ llvm/trunk/test/Transforms/InstSimplify/exp-intrinsic.ll Wed Jan 3 06:37:42 2018
@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+declare double @llvm.exp.f64(double)
+declare double @llvm.log.f64(double)
+
+define double @exp_log(double %a) {
+; CHECK-LABEL: @exp_log(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.log.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call double @llvm.log.f64(double %a)
+ %2 = call double @llvm.exp.f64(double %1)
+ ret double %2
+}
+
+define double @exp_log_fast(double %a) {
+; CHECK-LABEL: @exp_log_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.log.f64(double %a)
+ %2 = call fast double @llvm.exp.f64(double %1)
+ ret double %2
+}
+
+define double @exp_fast_log_strict(double %a) {
+; CHECK-LABEL: @exp_fast_log_strict(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call double @llvm.log.f64(double %a)
+ %2 = call fast double @llvm.exp.f64(double %1)
+ ret double %2
+}
+
+define double @exp_strict_log_fast(double %a) {
+; CHECK-LABEL: @exp_strict_log_fast(
+; CHECK-NEXT: [[TMP1:%.*]] = call fast double @llvm.log.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call fast double @llvm.log.f64(double %a)
+ %2 = call double @llvm.exp.f64(double %1)
+ ret double %2
+}
+
+define double @exp_log_exp_log(double %a) {
+; CHECK-LABEL: @exp_log_exp_log(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.log.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp.f64(double [[TMP1]])
+; CHECK-NEXT: [[TMP3:%.*]] = call double @llvm.log.f64(double [[TMP2]])
+; CHECK-NEXT: [[TMP4:%.*]] = call double @llvm.exp.f64(double [[TMP3]])
+; CHECK-NEXT: ret double [[TMP4]]
+;
+ %1 = call double @llvm.log.f64(double %a)
+ %2 = call double @llvm.exp.f64(double %1)
+ %3 = call double @llvm.log.f64(double %2)
+ %4 = call double @llvm.exp.f64(double %3)
+ ret double %4
+}
+
+define double @exp_log_exp_log_fast(double %a) {
+; CHECK-LABEL: @exp_log_exp_log_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.log.f64(double %a)
+ %2 = call fast double @llvm.exp.f64(double %1)
+ %3 = call fast double @llvm.log.f64(double %2)
+ %4 = call fast double @llvm.exp.f64(double %3)
+ ret double %4
+}
Added: llvm/trunk/test/Transforms/InstSimplify/exp2-intrinsic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/exp2-intrinsic.ll?rev=321710&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/exp2-intrinsic.ll (added)
+++ llvm/trunk/test/Transforms/InstSimplify/exp2-intrinsic.ll Wed Jan 3 06:37:42 2018
@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+declare double @llvm.exp2.f64(double)
+declare double @llvm.log2.f64(double)
+
+define double @exp2_log2(double %a) {
+; CHECK-LABEL: @exp2_log2(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.log2.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp2.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call double @llvm.log2.f64(double %a)
+ %2 = call double @llvm.exp2.f64(double %1)
+ ret double %2
+}
+
+define double @exp2_log2_fast(double %a) {
+; CHECK-LABEL: @exp2_log2_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.log2.f64(double %a)
+ %2 = call fast double @llvm.exp2.f64(double %1)
+ ret double %2
+}
+
+define double @exp2_fast_log2_strict(double %a) {
+; CHECK-LABEL: @exp2_fast_log2_strict(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call double @llvm.log2.f64(double %a)
+ %2 = call fast double @llvm.exp2.f64(double %1)
+ ret double %2
+}
+
+define double @exp2_strict_log2_fast(double %a) {
+; CHECK-LABEL: @exp2_strict_log2_fast(
+; CHECK-NEXT: [[TMP1:%.*]] = call fast double @llvm.log2.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp2.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call fast double @llvm.log2.f64(double %a)
+ %2 = call double @llvm.exp2.f64(double %1)
+ ret double %2
+}
+
+define double @exp2_log2_exp2_log2(double %a) {
+; CHECK-LABEL: @exp2_log2_exp2_log2(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.log2.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp2.f64(double [[TMP1]])
+; CHECK-NEXT: [[TMP3:%.*]] = call double @llvm.log2.f64(double [[TMP2]])
+; CHECK-NEXT: [[TMP4:%.*]] = call double @llvm.exp2.f64(double [[TMP3]])
+; CHECK-NEXT: ret double [[TMP4]]
+;
+ %1 = call double @llvm.log2.f64(double %a)
+ %2 = call double @llvm.exp2.f64(double %1)
+ %3 = call double @llvm.log2.f64(double %2)
+ %4 = call double @llvm.exp2.f64(double %3)
+ ret double %4
+}
+
+define double @exp2_log2_exp2_log2_fast(double %a) {
+; CHECK-LABEL: @exp2_log2_exp2_log2_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.log2.f64(double %a)
+ %2 = call fast double @llvm.exp2.f64(double %1)
+ %3 = call fast double @llvm.log2.f64(double %2)
+ %4 = call fast double @llvm.exp2.f64(double %3)
+ ret double %4
+}
Added: llvm/trunk/test/Transforms/InstSimplify/log-intrinsic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/log-intrinsic.ll?rev=321710&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/log-intrinsic.ll (added)
+++ llvm/trunk/test/Transforms/InstSimplify/log-intrinsic.ll Wed Jan 3 06:37:42 2018
@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+declare double @llvm.log.f64(double)
+declare double @llvm.exp.f64(double)
+
+define double @log_exp(double %a) {
+; CHECK-LABEL: @log_exp(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.log.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call double @llvm.exp.f64(double %a)
+ %2 = call double @llvm.log.f64(double %1)
+ ret double %2
+}
+
+define double @log_exp_fast(double %a) {
+; CHECK-LABEL: @log_exp_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.exp.f64(double %a)
+ %2 = call fast double @llvm.log.f64(double %1)
+ ret double %2
+}
+
+define double @log_fast_exp_strict(double %a) {
+; CHECK-LABEL: @log_fast_exp_strict(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call double @llvm.exp.f64(double %a)
+ %2 = call fast double @llvm.log.f64(double %1)
+ ret double %2
+}
+
+define double @log_strict_exp_fast(double %a) {
+; CHECK-LABEL: @log_strict_exp_fast(
+; CHECK-NEXT: [[TMP1:%.*]] = call fast double @llvm.exp.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.log.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call fast double @llvm.exp.f64(double %a)
+ %2 = call double @llvm.log.f64(double %1)
+ ret double %2
+}
+
+define double @log_exp_log_exp(double %a) {
+; CHECK-LABEL: @log_exp_log_exp(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.log.f64(double [[TMP1]])
+; CHECK-NEXT: [[TMP3:%.*]] = call double @llvm.exp.f64(double [[TMP2]])
+; CHECK-NEXT: [[TMP4:%.*]] = call double @llvm.log.f64(double [[TMP3]])
+; CHECK-NEXT: ret double [[TMP4]]
+;
+ %1 = call double @llvm.exp.f64(double %a)
+ %2 = call double @llvm.log.f64(double %1)
+ %3 = call double @llvm.exp.f64(double %2)
+ %4 = call double @llvm.log.f64(double %3)
+ ret double %4
+}
+
+define double @log_exp_log_exp_fast(double %a) {
+; CHECK-LABEL: @log_exp_log_exp_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.exp.f64(double %a)
+ %2 = call fast double @llvm.log.f64(double %1)
+ %3 = call fast double @llvm.exp.f64(double %2)
+ %4 = call fast double @llvm.log.f64(double %3)
+ ret double %4
+}
Added: llvm/trunk/test/Transforms/InstSimplify/log2-intrinsic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/log2-intrinsic.ll?rev=321710&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/log2-intrinsic.ll (added)
+++ llvm/trunk/test/Transforms/InstSimplify/log2-intrinsic.ll Wed Jan 3 06:37:42 2018
@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+declare double @llvm.log2.f64(double)
+declare double @llvm.exp2.f64(double)
+
+define double @log2_exp2(double %a) {
+; CHECK-LABEL: @log2_exp2(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp2.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.log2.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call double @llvm.exp2.f64(double %a)
+ %2 = call double @llvm.log2.f64(double %1)
+ ret double %2
+}
+
+define double @log2_exp2_fast(double %a) {
+; CHECK-LABEL: @log2_exp2_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.exp2.f64(double %a)
+ %2 = call fast double @llvm.log2.f64(double %1)
+ ret double %2
+}
+
+define double @log2_fast_exp2_strict(double %a) {
+; CHECK-LABEL: @log2_fast_exp2_strict(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call double @llvm.exp2.f64(double %a)
+ %2 = call fast double @llvm.log2.f64(double %1)
+ ret double %2
+}
+
+define double @log2_strict_exp2_fast(double %a) {
+; CHECK-LABEL: @log2_strict_exp2_fast(
+; CHECK-NEXT: [[TMP1:%.*]] = call fast double @llvm.exp2.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.log2.f64(double [[TMP1]])
+; CHECK-NEXT: ret double [[TMP2]]
+;
+ %1 = call fast double @llvm.exp2.f64(double %a)
+ %2 = call double @llvm.log2.f64(double %1)
+ ret double %2
+}
+
+define double @log2_exp2_log2_exp2(double %a) {
+; CHECK-LABEL: @log2_exp2_log2_exp2(
+; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp2.f64(double [[A:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.log2.f64(double [[TMP1]])
+; CHECK-NEXT: [[TMP3:%.*]] = call double @llvm.exp2.f64(double [[TMP2]])
+; CHECK-NEXT: [[TMP4:%.*]] = call double @llvm.log2.f64(double [[TMP3]])
+; CHECK-NEXT: ret double [[TMP4]]
+;
+ %1 = call double @llvm.exp2.f64(double %a)
+ %2 = call double @llvm.log2.f64(double %1)
+ %3 = call double @llvm.exp2.f64(double %2)
+ %4 = call double @llvm.log2.f64(double %3)
+ ret double %4
+}
+
+define double @log2_exp2_log2_exp2_fast(double %a) {
+; CHECK-LABEL: @log2_exp2_log2_exp2_fast(
+; CHECK-NEXT: ret double [[A:%.*]]
+;
+ %1 = call fast double @llvm.exp2.f64(double %a)
+ %2 = call fast double @llvm.log2.f64(double %1)
+ %3 = call fast double @llvm.exp2.f64(double %2)
+ %4 = call fast double @llvm.log2.f64(double %3)
+ ret double %4
+}
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