mirror of
https://github.com/c64scene-ar/llvm-6502.git
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5e6cabd163
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
45 lines
1.3 KiB
LLVM
45 lines
1.3 KiB
LLVM
; RUN: opt < %s -instcombine -S | FileCheck %s
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;; Target triple for gep raising case below.
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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"
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target triple = "i686-apple-darwin8"
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define float @test1(float %A, float %B, i1 %C) {
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EntryBlock:
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;; select C, 0, B + select C, A, 0 -> select C, A, B
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%cf = uitofp i1 %C to float
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%s1 = select i1 %C, float 0.000000e+00, float %B
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%s2 = select i1 %C, float %A, float 0.000000e+00
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%sum = fadd fast float %s1, %s2
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ret float %sum
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; CHECK: @test1
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; CHECK: select i1 %C, float %A, float %B
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}
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define float @test2(float %A, float %B, i1 %C) {
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EntryBlock:
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;; B*(uitofp i1 C) + A*(1 - uitofp i1 C) -> select C, A, B
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%cf = uitofp i1 %C to float
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%mc = fsub fast float 1.000000e+00, %cf
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%p1 = fmul fast float %A, %mc
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%p2 = fmul fast float %B, %cf
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%s1 = fadd fast float %p2, %p1
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ret float %s1
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; CHECK: @test2
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; CHECK: select i1 %C, float %B, float %A
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}
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define float @test3(float %A, float %B, i1 %C) {
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EntryBlock:
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;; A*(1 - uitofp i1 C) + B*(uitofp i1 C) -> select C, A, B
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%cf = uitofp i1 %C to float
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%mc = fsub fast float 1.000000e+00, %cf
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%p1 = fmul fast float %A, %mc
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%p2 = fmul fast float %B, %cf
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%s1 = fadd fast float %p1, %p2
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ret float %s1
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; CHECK: @test3
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; CHECK: select i1 %C, float %B, float %A
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}
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