llvm-project/llvm/test/Transforms/Reassociate/reassoc-intermediate-fnegs.ll

38 lines
1.3 KiB
LLVM

; RUN: opt < %s -reassociate -S | FileCheck %s
; Input is A op (B op C)
define half @faddsubAssoc1(half %a, half %b) {
; CHECK-LABEL: @faddsubAssoc1(
; CHECK-NEXT: [[T2_NEG:%.*]] = fmul fast half %a, 0xH4500
; CHECK-NEXT: [[REASS_MUL:%.*]] = fmul fast half %b, 0xH4500
; CHECK-NEXT: [[T51:%.*]] = fsub fast half [[REASS_MUL]], [[T2_NEG]]
; CHECK-NEXT: [[T5:%.*]] = fadd fast half [[REASS_MUL]], [[T2_NEG]]
; CHECK-NEXT: ret half [[T51]]
;
%t1 = fmul fast half %b, 0xH4200 ; 3*b
%t2 = fmul fast half %a, 0xH4500 ; 5*a
%t3 = fmul fast half %b, 0xH4000 ; 2*b
%t4 = fsub fast half %t2, %t1 ; 5 * a - 3 * b
%t5 = fsub fast half %t3, %t4 ; 2 * b - ( 5 * a - 3 * b)
ret half %t5 ; = 5 * (b - a)
}
; Input is (A op B) op C
define half @faddsubAssoc2(half %a, half %b) {
; CHECK-LABEL: @faddsubAssoc2(
; CHECK-NEXT: [[T2:%.*]] = fmul fast half %a, 0xH4500
; CHECK-NEXT: [[REASS_MUL:%.*]] = fmul fast half %b, 0xH3C00
; CHECK-NEXT: [[T5:%.*]] = fadd fast half [[REASS_MUL]], [[T2]]
; CHECK-NEXT: ret half [[T5]]
;
%t1 = fmul fast half %b, 0xH4200 ; 3*b
%t2 = fmul fast half %a, 0xH4500 ; 5*a
%t3 = fmul fast half %b, 0xH4000 ; 2*b
%t4 = fadd fast half %t2, %t1 ; 5 * a + 3 * b
%t5 = fsub fast half %t4, %t3 ; (5 * a + 3 * b) - (2 * b)
ret half %t5 ; = 5 * a + b
}