llvm-6502/test/Transforms/InstCombine/add4.ll
Jean-Luc Duprat 5e6cabd163 This is an update to a previous commit (r181216).
The earlier change list introduced the following inst combines:
B * (uitofp i1 C) —> select C, B, 0
A * (1 - uitofp i1 C) —> select C, 0, A
select C, 0, B + select C, A, 0 —> select C, A, B

Together these 3 changes would simplify :
A * (1 - uitofp i1 C) + B * uitofp i1 C 
down to :
select C, B, A

In practice we found that the first two substitutions can have a
negative effect on performance, because they reduce opportunities to
use FMA contractions; between the two options FMAs are often the
better choice.  This change list amends the previous one to enable
just these inst combines:

select C, B, 0 + select C, 0, A —> select C, B, A
A * (1 - uitofp i1 C) + B * uitofp i1 C —> select C, B, A




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182499 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-22 18:29:31 +00:00

45 lines
1.3 KiB
LLVM

; RUN: opt < %s -instcombine -S | FileCheck %s
;; Target triple for gep raising case below.
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i686-apple-darwin8"
define float @test1(float %A, float %B, i1 %C) {
EntryBlock:
;; select C, 0, B + select C, A, 0 -> select C, A, B
%cf = uitofp i1 %C to float
%s1 = select i1 %C, float 0.000000e+00, float %B
%s2 = select i1 %C, float %A, float 0.000000e+00
%sum = fadd fast float %s1, %s2
ret float %sum
; CHECK: @test1
; CHECK: select i1 %C, float %A, float %B
}
define float @test2(float %A, float %B, i1 %C) {
EntryBlock:
;; B*(uitofp i1 C) + A*(1 - uitofp i1 C) -> select C, A, B
%cf = uitofp i1 %C to float
%mc = fsub fast float 1.000000e+00, %cf
%p1 = fmul fast float %A, %mc
%p2 = fmul fast float %B, %cf
%s1 = fadd fast float %p2, %p1
ret float %s1
; CHECK: @test2
; CHECK: select i1 %C, float %B, float %A
}
define float @test3(float %A, float %B, i1 %C) {
EntryBlock:
;; A*(1 - uitofp i1 C) + B*(uitofp i1 C) -> select C, A, B
%cf = uitofp i1 %C to float
%mc = fsub fast float 1.000000e+00, %cf
%p1 = fmul fast float %A, %mc
%p2 = fmul fast float %B, %cf
%s1 = fadd fast float %p1, %p2
ret float %s1
; CHECK: @test3
; CHECK: select i1 %C, float %B, float %A
}