1 ; RUN: opt < %s -reassociate -constprop -instcombine -S | FileCheck %s 2 3 define float @test1(float %A, float %B) { 4 ; CHECK-LABEL: @test1( 5 ; CHECK-NEXT: [[W:%.*]] = fadd float %B, 5.000000e+00 6 ; CHECK-NEXT: [[X:%.*]] = fadd float %A, -7.000000e+00 7 ; CHECK-NEXT: [[Y:%.*]] = fsub float [[X]], [[W]] 8 ; CHECK-NEXT: [[Z:%.*]] = fadd float [[Y]], 1.200000e+01 9 ; CHECK-NEXT: ret float [[Z]] 10 ; 11 %W = fadd float 5.0, %B 12 %X = fadd float -7.0, %A 13 %Y = fsub float %X, %W 14 %Z = fadd float %Y, 12.0 15 ret float %Z 16 } 17 18 ; With sub reassociation, constant folding can eliminate all of the constants. 19 define float @test2(float %A, float %B) { 20 ; CHECK-LABEL: @test2( 21 ; CHECK-NEXT: [[Z:%.*]] = fsub fast float %A, %B 22 ; CHECK-NEXT: ret float [[Z]] 23 ; 24 %W = fadd fast float %B, 5.000000e+00 25 %X = fadd fast float %A, -7.000000e+00 26 %Y = fsub fast float %X, %W 27 %Z = fadd fast float %Y, 1.200000e+01 28 ret float %Z 29 } 30 31 ; Check again using minimal subset of FMF. 32 ; Both 'reassoc' and 'nsz' are required. 33 define float @test2_minimal(float %A, float %B) { 34 ; CHECK-LABEL: @test2_minimal( 35 ; CHECK-NEXT: [[Z:%.*]] = fsub reassoc nsz float %A, %B 36 ; CHECK-NEXT: ret float [[Z]] 37 ; 38 %W = fadd reassoc nsz float %B, 5.000000e+00 39 %X = fadd reassoc nsz float %A, -7.000000e+00 40 %Y = fsub reassoc nsz float %X, %W 41 %Z = fadd reassoc nsz float %Y, 1.200000e+01 42 ret float %Z 43 } 44 45 ; Verify the fold is not done with only 'reassoc' ('nsz' is required). 46 define float @test2_reassoc(float %A, float %B) { 47 ; CHECK-LABEL: @test2_reassoc( 48 ; CHECK-NEXT: [[W:%.*]] = fadd reassoc float %B, 5.000000e+00 49 ; CHECK-NEXT: [[X:%.*]] = fadd reassoc float %A, -7.000000e+00 50 ; CHECK-NEXT: [[Y:%.*]] = fsub reassoc float [[X]], [[W]] 51 ; CHECK-NEXT: [[Z:%.*]] = fadd reassoc float [[Y]], 1.200000e+01 52 ; CHECK-NEXT: ret float [[Z]] 53 ; 54 %W = fadd reassoc float %B, 5.000000e+00 55 %X = fadd reassoc float %A, -7.000000e+00 56 %Y = fsub reassoc float %X, %W 57 %Z = fadd reassoc float %Y, 1.200000e+01 58 ret float %Z 59 } 60 61 define float @test3(float %A, float %B, float %C, float %D) { 62 ; CHECK-LABEL: @test3( 63 ; CHECK-NEXT: [[M:%.*]] = fadd float %A, 1.200000e+01 64 ; CHECK-NEXT: [[N:%.*]] = fadd float [[M]], %B 65 ; CHECK-NEXT: [[O:%.*]] = fadd float [[N]], %C 66 ; CHECK-NEXT: [[P:%.*]] = fsub float %D, [[O]] 67 ; CHECK-NEXT: [[Q:%.*]] = fadd float [[P]], 1.200000e+01 68 ; CHECK-NEXT: ret float [[Q]] 69 ; 70 %M = fadd float %A, 1.200000e+01 71 %N = fadd float %M, %B 72 %O = fadd float %N, %C 73 %P = fsub float %D, %O 74 %Q = fadd float %P, 1.200000e+01 75 ret float %Q 76 } 77 78 ; With sub reassociation, constant folding can eliminate the two 12 constants. 79 80 define float @test4(float %A, float %B, float %C, float %D) { 81 ; FIXME: InstCombine should be able to get us to the following: 82 ; %sum = fadd fast float %B, %A 83 ; %sum1 = fadd fast float %sum, %C 84 ; %Q = fsub fast float %D, %sum1 85 ; ret i32 %Q 86 ; CHECK-LABEL: @test4( 87 ; CHECK-NEXT: [[B_NEG:%.*]] = fsub fast float -0.000000e+00, %B 88 ; CHECK-NEXT: [[O_NEG:%.*]] = fsub fast float [[B_NEG]], %A 89 ; CHECK-NEXT: [[P:%.*]] = fsub fast float [[O_NEG]], %C 90 ; CHECK-NEXT: [[Q:%.*]] = fadd fast float [[P]], %D 91 ; CHECK-NEXT: ret float [[Q]] 92 ; 93 %M = fadd fast float 1.200000e+01, %A 94 %N = fadd fast float %M, %B 95 %O = fadd fast float %N, %C 96 %P = fsub fast float %D, %O 97 %Q = fadd fast float 1.200000e+01, %P 98 ret float %Q 99 } 100 101 ; Check again using minimal subset of FMF. 102 103 define float @test4_reassoc(float %A, float %B, float %C, float %D) { 104 ; CHECK-LABEL: @test4_reassoc( 105 ; CHECK-NEXT: [[M:%.*]] = fadd reassoc float %A, 1.200000e+01 106 ; CHECK-NEXT: [[N:%.*]] = fadd reassoc float [[M]], %B 107 ; CHECK-NEXT: [[O:%.*]] = fadd reassoc float [[N]], %C 108 ; CHECK-NEXT: [[P:%.*]] = fsub reassoc float %D, [[O]] 109 ; CHECK-NEXT: [[Q:%.*]] = fadd reassoc float [[P]], 1.200000e+01 110 ; CHECK-NEXT: ret float [[Q]] 111 ; 112 %M = fadd reassoc float 1.200000e+01, %A 113 %N = fadd reassoc float %M, %B 114 %O = fadd reassoc float %N, %C 115 %P = fsub reassoc float %D, %O 116 %Q = fadd reassoc float 1.200000e+01, %P 117 ret float %Q 118 } 119 120
