llvm-project/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll

62 lines
1.5 KiB
LLVM

; RUN: opt < %s -instsimplify -S | FileCheck %s
; fsub 0, (fsub 0, X) ==> X
; CHECK-LABEL: @fsub_0_0_x(
define float @fsub_0_0_x(float %a) {
%t1 = fsub float -0.0, %a
%ret = fsub float -0.0, %t1
; CHECK: ret float %a
ret float %ret
}
; fsub X, 0 ==> X
; CHECK-LABEL: @fsub_x_0(
define float @fsub_x_0(float %a) {
%ret = fsub float %a, 0.0
; CHECK: ret float %a
ret float %ret
}
; fadd X, -0 ==> X
; CHECK-LABEL: @fadd_x_n0(
define float @fadd_x_n0(float %a) {
%ret = fadd float %a, -0.0
; CHECK: ret float %a
ret float %ret
}
; fmul X, 1.0 ==> X
; CHECK-LABEL: @fmul_X_1(
define double @fmul_X_1(double %a) {
%b = fmul double 1.000000e+00, %a ; <double> [#uses=1]
; CHECK: ret double %a
ret double %b
}
; We can't optimize away the fadd in this test because the input
; value to the function and subsequently to the fadd may be -0.0.
; In that one special case, the result of the fadd should be +0.0
; rather than the first parameter of the fadd.
; Fragile test warning: We need 6 sqrt calls to trigger the bug
; because the internal logic has a magic recursion limit of 6.
; This is presented without any explanation or ability to customize.
declare float @sqrtf(float)
define float @PR22688(float %x) {
%1 = call float @sqrtf(float %x)
%2 = call float @sqrtf(float %1)
%3 = call float @sqrtf(float %2)
%4 = call float @sqrtf(float %3)
%5 = call float @sqrtf(float %4)
%6 = call float @sqrtf(float %5)
%7 = fadd float %6, 0.0
ret float %7
; CHECK-LABEL: @PR22688(
; CHECK: fadd float %6, 0.0
}