; RUN: opt < %s -reassociate -constprop -instcombine -S | FileCheck %s define float @test1(float %A, float %B) { ; CHECK-LABEL: @test1( ; CHECK-NEXT: [[W:%.*]] = fadd float %B, 5.000000e+00 ; CHECK-NEXT: [[X:%.*]] = fadd float %A, -7.000000e+00 ; CHECK-NEXT: [[Y:%.*]] = fsub float [[X]], [[W]] ; CHECK-NEXT: [[Z:%.*]] = fadd float [[Y]], 1.200000e+01 ; CHECK-NEXT: ret float [[Z]] ; %W = fadd float 5.0, %B %X = fadd float -7.0, %A %Y = fsub float %X, %W %Z = fadd float %Y, 12.0 ret float %Z } ; With sub reassociation, constant folding can eliminate all of the constants. define float @test2(float %A, float %B) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: [[Z:%.*]] = fsub fast float %A, %B ; CHECK-NEXT: ret float [[Z]] ; %W = fadd fast float %B, 5.000000e+00 %X = fadd fast float %A, -7.000000e+00 %Y = fsub fast float %X, %W %Z = fadd fast float %Y, 1.200000e+01 ret float %Z } ; Check again using minimal subset of FMF. define float @test2_reassoc(float %A, float %B) { ; CHECK-LABEL: @test2_reassoc( ; CHECK-NEXT: [[W:%.*]] = fadd reassoc float %B, 5.000000e+00 ; CHECK-NEXT: [[X:%.*]] = fadd reassoc float %A, -7.000000e+00 ; CHECK-NEXT: [[Y:%.*]] = fsub reassoc float [[X]], [[W]] ; CHECK-NEXT: [[Z:%.*]] = fadd reassoc float [[Y]], 1.200000e+01 ; CHECK-NEXT: ret float [[Z]] ; %W = fadd reassoc float %B, 5.000000e+00 %X = fadd reassoc float %A, -7.000000e+00 %Y = fsub reassoc float %X, %W %Z = fadd reassoc float %Y, 1.200000e+01 ret float %Z } define float @test3(float %A, float %B, float %C, float %D) { ; CHECK-LABEL: @test3( ; CHECK-NEXT: [[M:%.*]] = fadd float %A, 1.200000e+01 ; CHECK-NEXT: [[N:%.*]] = fadd float [[M]], %B ; CHECK-NEXT: [[O:%.*]] = fadd float [[N]], %C ; CHECK-NEXT: [[P:%.*]] = fsub float %D, [[O]] ; CHECK-NEXT: [[Q:%.*]] = fadd float [[P]], 1.200000e+01 ; CHECK-NEXT: ret float [[Q]] ; %M = fadd float %A, 1.200000e+01 %N = fadd float %M, %B %O = fadd float %N, %C %P = fsub float %D, %O %Q = fadd float %P, 1.200000e+01 ret float %Q } ; With sub reassociation, constant folding can eliminate the two 12 constants. define float @test4(float %A, float %B, float %C, float %D) { ; FIXME: InstCombine should be able to get us to the following: ; %sum = fadd fast float %B, %A ; %sum1 = fadd fast float %sum, %C ; %Q = fsub fast float %D, %sum1 ; ret i32 %Q ; CHECK-LABEL: @test4( ; CHECK-NEXT: [[B_NEG:%.*]] = fsub fast float -0.000000e+00, %B ; CHECK-NEXT: [[O_NEG:%.*]] = fsub fast float [[B_NEG]], %A ; CHECK-NEXT: [[P:%.*]] = fsub fast float [[O_NEG]], %C ; CHECK-NEXT: [[Q:%.*]] = fadd fast float [[P]], %D ; CHECK-NEXT: ret float [[Q]] ; %M = fadd fast float 1.200000e+01, %A %N = fadd fast float %M, %B %O = fadd fast float %N, %C %P = fsub fast float %D, %O %Q = fadd fast float 1.200000e+01, %P ret float %Q } ; Check again using minimal subset of FMF. define float @test4_reassoc(float %A, float %B, float %C, float %D) { ; CHECK-LABEL: @test4_reassoc( ; CHECK-NEXT: [[M:%.*]] = fadd reassoc float %A, 1.200000e+01 ; CHECK-NEXT: [[N:%.*]] = fadd reassoc float [[M]], %B ; CHECK-NEXT: [[O:%.*]] = fadd reassoc float [[N]], %C ; CHECK-NEXT: [[P:%.*]] = fsub reassoc float %D, [[O]] ; CHECK-NEXT: [[Q:%.*]] = fadd reassoc float [[P]], 1.200000e+01 ; CHECK-NEXT: ret float [[Q]] ; %M = fadd reassoc float 1.200000e+01, %A %N = fadd reassoc float %M, %B %O = fadd reassoc float %N, %C %P = fsub reassoc float %D, %O %Q = fadd reassoc float 1.200000e+01, %P ret float %Q }