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InstCombine: Add baseline test for #64697 fmul reassociation #171725

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Merged
arsenm merged 1 commit into from
Dec 11, 2025
Merged

InstCombine: Add baseline test for #64697 fmul reassociation #171725

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117 changes: 117 additions & 0 deletions llvm/test/Transforms/InstCombine/issue64967-reassoc-fmul.ll
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Original file line number Diff line number Diff line change
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt -S -passes=instcombine < %s | FileCheck %s

; Show that unlike fadd, fmul does not require nsz to be reassociated.

; Can't reassociate anyway
define float @fmul(float %x) {
; CHECK-LABEL: define float @fmul(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[FMUL0:%.*]] = fmul float [[X]], 2.000000e+00
; CHECK-NEXT: [[FMUL1:%.*]] = fmul float [[FMUL0]], 4.000000e+00
; CHECK-NEXT: ret float [[FMUL1]]
;
%fmul0 = fmul float %x, 2.0
%fmul1 = fmul float %fmul0, 4.0
ret float %fmul1
}

; Should be able to reassociate without nsz
; (+0 * 2) * 4 = +0
; (-0 * 2) * 4 = -0

; (+0 * 8) = +0
; (-0 * 8) = -0
define float @fmul_reassoc(float %x) {
; CHECK-LABEL: define float @fmul_reassoc(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[FMUL0:%.*]] = fmul reassoc float [[X]], 2.000000e+00
; CHECK-NEXT: [[FMUL1:%.*]] = fmul reassoc float [[FMUL0]], 4.000000e+00
; CHECK-NEXT: ret float [[FMUL1]]
;
%fmul0 = fmul reassoc float %x, 2.0
%fmul1 = fmul reassoc float %fmul0, 4.0
ret float %fmul1
}

define <2 x float> @fmul_reassoc_v2(<2 x float> %x) {
; CHECK-LABEL: define <2 x float> @fmul_reassoc_v2(
; CHECK-SAME: <2 x float> [[X:%.*]]) {
; CHECK-NEXT: [[FMUL0:%.*]] = fmul reassoc <2 x float> [[X]], splat (float 2.000000e+00)
; CHECK-NEXT: [[FMUL1:%.*]] = fmul reassoc <2 x float> [[FMUL0]], splat (float 4.000000e+00)
; CHECK-NEXT: ret <2 x float> [[FMUL1]]
;
%fmul0 = fmul reassoc <2 x float> %x, splat (float 2.0)
%fmul1 = fmul reassoc <2 x float> %fmul0, splat (float 4.0)
ret <2 x float> %fmul1
}

; (+0 * 2) * -4 = -0
; (-0 * 2) * -4 = +0

; (+0 * -8) = -0
; (-0 * -8) = +0
define float @fmul_reassoc_negative_0(float %x) {
; CHECK-LABEL: define float @fmul_reassoc_negative_0(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[FMUL0:%.*]] = fmul reassoc float [[X]], 2.000000e+00
; CHECK-NEXT: [[FMUL1:%.*]] = fmul reassoc float [[FMUL0]], -4.000000e+00
; CHECK-NEXT: ret float [[FMUL1]]
;
%fmul0 = fmul reassoc float %x, 2.0
%fmul1 = fmul reassoc float %fmul0, -4.0
ret float %fmul1
}

; (+0 * -2) * 4 = -0
; (-0 * -2) * 4 = +0

; (+0 * -8) = -0
; (-0 * -8) = +0
define float @fmul_reassoc_negative_1(float %x) {
; CHECK-LABEL: define float @fmul_reassoc_negative_1(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[FMUL0:%.*]] = fmul reassoc float [[X]], -2.000000e+00
; CHECK-NEXT: [[FMUL1:%.*]] = fmul reassoc float [[FMUL0]], 4.000000e+00
; CHECK-NEXT: ret float [[FMUL1]]
;
%fmul0 = fmul reassoc float %x, -2.0
%fmul1 = fmul reassoc float %fmul0, 4.0
ret float %fmul1
}

; Does reassociate already, unnecessarily requires nsz on both multiplies.
define float @fmul_reassoc_nsz(float %x) {
; CHECK-LABEL: define float @fmul_reassoc_nsz(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[FMUL1:%.*]] = fmul reassoc nsz float [[X]], 8.000000e+00
; CHECK-NEXT: ret float [[FMUL1]]
;
%fmul0 = fmul nsz reassoc float %x, 2.0
%fmul1 = fmul nsz reassoc float %fmul0, 4.0
ret float %fmul1
}

define float @fmul_reassoc_posk_neg0(float %x) {
; CHECK-LABEL: define float @fmul_reassoc_posk_neg0(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[FMUL0:%.*]] = fmul reassoc float [[X]], 4.000000e+00
; CHECK-NEXT: [[FMUL1:%.*]] = fmul reassoc float [[FMUL0]], -0.000000e+00
; CHECK-NEXT: ret float [[FMUL1]]
;
%fmul0 = fmul reassoc float %x, 4.0
%fmul1 = fmul reassoc float %fmul0, -0.0
ret float %fmul1
}

define float @fmul_reassoc_neg0_posk(float %x) {
; CHECK-LABEL: define float @fmul_reassoc_neg0_posk(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[FMUL0:%.*]] = fmul reassoc float [[X]], -0.000000e+00
; CHECK-NEXT: [[FMUL1:%.*]] = fmul reassoc float [[FMUL0]], 4.000000e+00
; CHECK-NEXT: ret float [[FMUL1]]
;
%fmul0 = fmul reassoc float %x, -0.0
%fmul1 = fmul reassoc float %fmul0, 4.0
ret float %fmul1
}