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llvm-project/llvm/test/Transforms/InstCombine/pow-exp-nofastmath.ll

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[InstCombine] regenerate checks; NFC llvm-svn: 339683
2018-08-14 23:21:13 +08:00
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
[SimplifyLibCalls] Add a new transformation: pow(exp(x), y) -> exp(x*y) This one is enabled only under -ffast-math (due to rounding/overflows) but allows us to emit shorter code. Before (on FreeBSD x86-64): 4007f0: 50 push %rax 4007f1: f2 0f 11 0c 24 movsd %xmm1,(%rsp) 4007f6: e8 75 fd ff ff callq 400570 <exp2@plt> 4007fb: f2 0f 10 0c 24 movsd (%rsp),%xmm1 400800: 58 pop %rax 400801: e9 7a fd ff ff jmpq 400580 <pow@plt> 400806: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 40080d: 00 00 00 After: 4007b0: f2 0f 59 c1 mulsd %xmm1,%xmm0 4007b4: e9 87 fd ff ff jmpq 400540 <exp2@plt> 4007b9: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) Differential Revision: http://reviews.llvm.org/D14045 llvm-svn: 251976
2015-11-04 04:32:23 +08:00
; RUN: opt < %s -instcombine -S | FileCheck %s
[InstCombine] regenerate checks; NFC llvm-svn: 339683
2018-08-14 23:21:13 +08:00
define double @mypow(double %x, double %y) {
; CHECK-LABEL: @mypow(
; CHECK-NEXT: [[CALL:%.*]] = call double @exp(double [[X:%.*]])
; CHECK-NEXT: [[POW:%.*]] = call double @llvm.pow.f64(double [[CALL]], double [[Y:%.*]])
; CHECK-NEXT: ret double [[POW]]
;
[SimplifyLibCalls] Add a new transformation: pow(exp(x), y) -> exp(x*y) This one is enabled only under -ffast-math (due to rounding/overflows) but allows us to emit shorter code. Before (on FreeBSD x86-64): 4007f0: 50 push %rax 4007f1: f2 0f 11 0c 24 movsd %xmm1,(%rsp) 4007f6: e8 75 fd ff ff callq 400570 <exp2@plt> 4007fb: f2 0f 10 0c 24 movsd (%rsp),%xmm1 400800: 58 pop %rax 400801: e9 7a fd ff ff jmpq 400580 <pow@plt> 400806: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 40080d: 00 00 00 After: 4007b0: f2 0f 59 c1 mulsd %xmm1,%xmm0 4007b4: e9 87 fd ff ff jmpq 400540 <exp2@plt> 4007b9: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) Differential Revision: http://reviews.llvm.org/D14045 llvm-svn: 251976
2015-11-04 04:32:23 +08:00
%call = call double @exp(double %x)
%pow = call double @llvm.pow.f64(double %call, double %y)
ret double %pow
}
declare double @exp(double) #1
declare double @llvm.pow.f64(double, double)