llvm-mirror/test/Transforms/InstSimplify/log2-pow2-intrinsic.ll
Dmitry Venikov c1c4330b2a [InstSimplify] Missed optimization in math expression: log10(pow(10.0,x)) == x, log2(pow(2.0,x)) == x
Summary: This patch enables folding following instructions under -ffast-math flag: log10(pow(10.0,x)) -> x, log2(pow(2.0,x)) -> x

Reviewers: hfinkel, spatel, efriedma, craig.topper, zvi, majnemer, lebedev.ri

Reviewed By: spatel, lebedev.ri

Subscribers: lebedev.ri, llvm-commits

Differential Revision: https://reviews.llvm.org/D41940

llvm-svn: 352981
2019-02-03 03:48:30 +00:00

46 lines
1.6 KiB
LLVM

; 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.pow.f64(double, double)
define double @log2_pow2(double %x) {
; CHECK-LABEL: @log2_pow2(
; CHECK-NEXT: [[TMP:%.*]] = call double @llvm.pow.f64(double 2.000000e+00, double [[X:%.*]])
; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.log2.f64(double [[TMP]])
; CHECK-NEXT: ret double [[TMP1]]
;
%tmp = call double @llvm.pow.f64(double 2.000000e+00, double %x)
%tmp1 = call double @llvm.log2.f64(double %tmp)
ret double %tmp1
}
define double @log2_strict_pow2_reassoc(double %x) {
; CHECK-LABEL: @log2_strict_pow2_reassoc(
; CHECK-NEXT: [[TMP:%.*]] = call reassoc double @llvm.pow.f64(double 2.000000e+00, double [[X:%.*]])
; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.log2.f64(double [[TMP]])
; CHECK-NEXT: ret double [[TMP1]]
;
%tmp = call reassoc double @llvm.pow.f64(double 2.000000e+00, double %x)
%tmp1 = call double @llvm.log2.f64(double %tmp)
ret double %tmp1
}
define double @log2_reassoc_pow2_strict(double %x) {
; CHECK-LABEL: @log2_reassoc_pow2_strict(
; CHECK-NEXT: ret double [[X:%.*]]
;
%tmp = call double @llvm.pow.f64(double 2.000000e+00, double %x)
%tmp1 = call reassoc double @llvm.log2.f64(double %tmp)
ret double %tmp1
}
define double @log2_pow2_reassoc(double %x) {
; CHECK-LABEL: @log2_pow2_reassoc(
; CHECK-NEXT: ret double [[X:%.*]]
;
%tmp = call reassoc double @llvm.pow.f64(double 2.000000e+00, double %x)
%tmp1 = call reassoc double @llvm.log2.f64(double %tmp)
ret double %tmp1
}