test/Transforms/InstCombine/fast-math.ll


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; RUN: opt < %s -instcombine -S | FileCheck %s

; testing-case "float fold(float a) { return 1.2f * a * 2.3f; }"
; 1.2f and 2.3f is supposed to be fold.
define float @fold(float %a) {
fold:
  %mul = fmul fast float %a, 0x3FF3333340000000
  %mul1 = fmul fast float %mul, 0x4002666660000000
  ret float %mul1
; CHECK: fold
; CHECK: fmul float %a, 0x4006147AE0000000
}

; Same testing-case as the one used in fold() except that the operators have
; fixed FP mode.
define float @notfold(float %a) {
notfold:
; CHECK: notfold
; CHECK: %mul = fmul fast float %a, 0x3FF3333340000000
  %mul = fmul fast float %a, 0x3FF3333340000000
  %mul1 = fmul float %mul, 0x4002666660000000
  ret float %mul1
}

define float @fold2(float %a) {
notfold2:
; CHECK: fold2
; CHECK: fmul float %a, 0x4006147AE0000000
  %mul = fmul float %a, 0x3FF3333340000000
  %mul1 = fmul fast float %mul, 0x4002666660000000
  ret float %mul1
}