[llvm] r352730 - [InstCombine] Missed optimization in math expression: simplify calls exp functions
Dmitry Venikov via llvm-commits
llvm-commits at lists.llvm.org
Wed Jan 30 22:28:10 PST 2019
Author: quolyk
Date: Wed Jan 30 22:28:10 2019
New Revision: 352730
URL: http://llvm.org/viewvc/llvm-project?rev=352730&view=rev
Log:
[InstCombine] Missed optimization in math expression: simplify calls exp functions
Summary: This patch enables folding following expressions under -ffast-math flag: exp(X) * exp(Y) -> exp(X + Y), exp2(X) * exp2(Y) -> exp2(X + Y). Motivation: https://bugs.llvm.org/show_bug.cgi?id=35594
Reviewers: hfinkel, spatel, efriedma, lebedev.ri
Reviewed By: spatel, lebedev.ri
Subscribers: lebedev.ri, llvm-commits
Differential Revision: https://reviews.llvm.org/D41342
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
llvm/trunk/test/Transforms/InstCombine/fmul-exp.ll
llvm/trunk/test/Transforms/InstCombine/fmul-exp2.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp?rev=352730&r1=352729&r2=352730&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp Wed Jan 30 22:28:10 2019
@@ -441,6 +441,26 @@ Instruction *InstCombiner::visitFMul(Bin
return replaceInstUsesWith(I, Sqrt);
}
+ // exp(X) * exp(Y) -> exp(X + Y)
+ // Match as long as at least one of exp has only one use.
+ if (match(Op0, m_Intrinsic<Intrinsic::exp>(m_Value(X))) &&
+ match(Op1, m_Intrinsic<Intrinsic::exp>(m_Value(Y))) &&
+ (Op0->hasOneUse() || Op1->hasOneUse())) {
+ Value *XY = Builder.CreateFAddFMF(X, Y, &I);
+ Value *Exp = Builder.CreateUnaryIntrinsic(Intrinsic::exp, XY, &I);
+ return replaceInstUsesWith(I, Exp);
+ }
+
+ // exp2(X) * exp2(Y) -> exp2(X + Y)
+ // Match as long as at least one of exp2 has only one use.
+ if (match(Op0, m_Intrinsic<Intrinsic::exp2>(m_Value(X))) &&
+ match(Op1, m_Intrinsic<Intrinsic::exp2>(m_Value(Y))) &&
+ (Op0->hasOneUse() || Op1->hasOneUse())) {
+ Value *XY = Builder.CreateFAddFMF(X, Y, &I);
+ Value *Exp2 = Builder.CreateUnaryIntrinsic(Intrinsic::exp2, XY, &I);
+ return replaceInstUsesWith(I, Exp2);
+ }
+
// (X*Y) * X => (X*X) * Y where Y != X
// The purpose is two-fold:
// 1) to form a power expression (of X).
Modified: llvm/trunk/test/Transforms/InstCombine/fmul-exp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fmul-exp.ll?rev=352730&r1=352729&r2=352730&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fmul-exp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fmul-exp.ll Wed Jan 30 22:28:10 2019
@@ -21,11 +21,11 @@ define double @exp_a_exp_b(double %a, do
; exp(a) * exp(b) reassoc, multiple uses
define double @exp_a_exp_b_multiple_uses(double %a, double %b) {
; CHECK-LABEL: @exp_a_exp_b_multiple_uses(
-; CHECK-NEXT: [[TMP:%.*]] = call double @llvm.exp.f64(double [[A:%.*]])
; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp.f64(double [[B:%.*]])
-; CHECK-NEXT: [[MUL:%.*]] = fmul reassoc double [[TMP]], [[TMP1]]
+; CHECK-NEXT: [[TMP:%.*]] = fadd reassoc double [[A:%.*]], [[B]]
+; CHECK-NEXT: [[TMP2:%.*]] = call reassoc double @llvm.exp.f64(double [[TMP]])
; CHECK-NEXT: call void @use(double [[TMP1]])
-; CHECK-NEXT: ret double [[MUL]]
+; CHECK-NEXT: ret double [[TMP2]]
;
%tmp = call double @llvm.exp.f64(double %a)
%tmp1 = call double @llvm.exp.f64(double %b)
@@ -55,10 +55,9 @@ define double @exp_a_exp_b_multiple_uses
; exp(a) * exp(b) => exp(a+b) with reassoc
define double @exp_a_exp_b_reassoc(double %a, double %b) {
; CHECK-LABEL: @exp_a_exp_b_reassoc(
-; CHECK-NEXT: [[TMP:%.*]] = call double @llvm.exp.f64(double [[A:%.*]])
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp.f64(double [[B:%.*]])
-; CHECK-NEXT: [[MUL:%.*]] = fmul reassoc double [[TMP]], [[TMP1]]
-; CHECK-NEXT: ret double [[MUL]]
+; CHECK-NEXT: [[TMP:%.*]] = fadd reassoc double [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT: [[TMP1:%.*]] = call reassoc double @llvm.exp.f64(double [[TMP]])
+; CHECK-NEXT: ret double [[TMP1]]
;
%tmp = call double @llvm.exp.f64(double %a)
%tmp1 = call double @llvm.exp.f64(double %b)
@@ -69,14 +68,11 @@ define double @exp_a_exp_b_reassoc(doubl
; exp(a) * exp(b) * exp(c) * exp(d) => exp(a+b+c+d) with reassoc
define double @exp_a_exp_b_exp_c_exp_d_fast(double %a, double %b, double %c, double %d) {
; CHECK-LABEL: @exp_a_exp_b_exp_c_exp_d_fast(
-; CHECK-NEXT: [[TMP:%.*]] = call double @llvm.exp.f64(double [[A:%.*]])
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp.f64(double [[B:%.*]])
-; CHECK-NEXT: [[MUL:%.*]] = fmul reassoc double [[TMP]], [[TMP1]]
-; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp.f64(double [[C:%.*]])
-; CHECK-NEXT: [[MUL1:%.*]] = fmul reassoc double [[MUL]], [[TMP2]]
-; CHECK-NEXT: [[TMP3:%.*]] = call double @llvm.exp.f64(double [[D:%.*]])
-; CHECK-NEXT: [[MUL2:%.*]] = fmul reassoc double [[MUL1]], [[TMP3]]
-; CHECK-NEXT: ret double [[MUL2]]
+; CHECK-NEXT: [[TMP:%.*]] = fadd reassoc double [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT: [[TMP1:%.*]] = fadd reassoc double [[TMP]], [[C:%.*]]
+; CHECK-NEXT: [[TMP2:%.*]] = fadd reassoc double [[TMP1]], [[D:%.*]]
+; CHECK-NEXT: [[TMP3:%.*]] = call reassoc double @llvm.exp.f64(double [[TMP2]])
+; CHECK-NEXT: ret double [[TMP3]]
;
%tmp = call double @llvm.exp.f64(double %a)
%tmp1 = call double @llvm.exp.f64(double %b)
Modified: llvm/trunk/test/Transforms/InstCombine/fmul-exp2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fmul-exp2.ll?rev=352730&r1=352729&r2=352730&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fmul-exp2.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fmul-exp2.ll Wed Jan 30 22:28:10 2019
@@ -21,11 +21,11 @@ define double @exp2_a_exp2_b(double %a,
; exp2(a) * exp2(b) reassoc, multiple uses
define double @exp2_a_exp2_b_multiple_uses(double %a, double %b) {
; CHECK-LABEL: @exp2_a_exp2_b_multiple_uses(
-; CHECK-NEXT: [[TMP:%.*]] = call double @llvm.exp2.f64(double [[A:%.*]])
; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp2.f64(double [[B:%.*]])
-; CHECK-NEXT: [[MUL:%.*]] = fmul reassoc double [[TMP]], [[TMP1]]
+; CHECK-NEXT: [[TMP:%.*]] = fadd reassoc double [[A:%.*]], [[B]]
+; CHECK-NEXT: [[TMP2:%.*]] = call reassoc double @llvm.exp2.f64(double [[TMP]])
; CHECK-NEXT: call void @use(double [[TMP1]])
-; CHECK-NEXT: ret double [[MUL]]
+; CHECK-NEXT: ret double [[TMP2]]
;
%tmp = call double @llvm.exp2.f64(double %a)
%tmp1 = call double @llvm.exp2.f64(double %b)
@@ -55,10 +55,9 @@ define double @exp2_a_exp2_b_multiple_us
; exp2(a) * exp2(b) => exp2(a+b) with reassoc
define double @exp2_a_exp2_b_reassoc(double %a, double %b) {
; CHECK-LABEL: @exp2_a_exp2_b_reassoc(
-; CHECK-NEXT: [[TMP:%.*]] = call double @llvm.exp2.f64(double [[A:%.*]])
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp2.f64(double [[B:%.*]])
-; CHECK-NEXT: [[MUL:%.*]] = fmul reassoc double [[TMP]], [[TMP1]]
-; CHECK-NEXT: ret double [[MUL]]
+; CHECK-NEXT: [[TMP:%.*]] = fadd reassoc double [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT: [[TMP1:%.*]] = call reassoc double @llvm.exp2.f64(double [[TMP]])
+; CHECK-NEXT: ret double [[TMP1]]
;
%tmp = call double @llvm.exp2.f64(double %a)
%tmp1 = call double @llvm.exp2.f64(double %b)
@@ -69,14 +68,11 @@ define double @exp2_a_exp2_b_reassoc(dou
; exp2(a) * exp2(b) * exp2(c) * exp2(d) => exp2(a+b+c+d) with reassoc
define double @exp2_a_exp2_b_exp2_c_exp2_d(double %a, double %b, double %c, double %d) {
; CHECK-LABEL: @exp2_a_exp2_b_exp2_c_exp2_d(
-; CHECK-NEXT: [[TMP:%.*]] = call double @llvm.exp2.f64(double [[A:%.*]])
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.exp2.f64(double [[B:%.*]])
-; CHECK-NEXT: [[MUL:%.*]] = fmul reassoc double [[TMP]], [[TMP1]]
-; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.exp2.f64(double [[C:%.*]])
-; CHECK-NEXT: [[MUL1:%.*]] = fmul reassoc double [[MUL]], [[TMP2]]
-; CHECK-NEXT: [[TMP3:%.*]] = call double @llvm.exp2.f64(double [[D:%.*]])
-; CHECK-NEXT: [[MUL2:%.*]] = fmul reassoc double [[MUL1]], [[TMP3]]
-; CHECK-NEXT: ret double [[MUL2]]
+; CHECK-NEXT: [[TMP:%.*]] = fadd reassoc double [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT: [[TMP1:%.*]] = fadd reassoc double [[TMP]], [[C:%.*]]
+; CHECK-NEXT: [[TMP2:%.*]] = fadd reassoc double [[TMP1]], [[D:%.*]]
+; CHECK-NEXT: [[TMP3:%.*]] = call reassoc double @llvm.exp2.f64(double [[TMP2]])
+; CHECK-NEXT: ret double [[TMP3]]
;
%tmp = call double @llvm.exp2.f64(double %a)
%tmp1 = call double @llvm.exp2.f64(double %b)
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