; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; ; Test numbering remains continuous across: ; - InstCombine/fast-basictest.ll ; - PhaseOrdering/fast-basictest.ll ; - PhaseOrdering/fast-reassociate-gvn.ll ; - Reassociate/fast-basictest.ll ; ; RUN: opt < %s -reassociate -S | FileCheck %s ; ((a + (-3)) + b) + 3 -> a + b ; That only works with both instcombine and reassociate passes enabled. ; Check that reassociate is not enough. ; TODO: check if we can eliminate zero add. define float @test2(float %reg109, float %reg1111) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: [[REG116:%.*]] = fadd fast float [[REG109:%.*]], 0.000000e+00 ; CHECK-NEXT: [[REG117:%.*]] = fadd fast float [[REG116]], [[REG1111:%.*]] ; CHECK-NEXT: ret float [[REG117]] ; %reg115 = fadd fast float %reg109, -3.000000e+01 %reg116 = fadd fast float %reg115, %reg1111 %reg117 = fadd fast float %reg116, 3.000000e+01 ret float %reg117 } define float @test2_no_FMF(float %reg109, float %reg1111) { ; CHECK-LABEL: @test2_no_FMF( ; CHECK-NEXT: [[REG115:%.*]] = fadd float [[REG109:%.*]], -3.000000e+01 ; CHECK-NEXT: [[REG116:%.*]] = fadd float [[REG115]], [[REG1111:%.*]] ; CHECK-NEXT: [[REG117:%.*]] = fadd float [[REG116]], 3.000000e+01 ; CHECK-NEXT: ret float [[REG117]] ; %reg115 = fadd float %reg109, -3.000000e+01 %reg116 = fadd float %reg115, %reg1111 %reg117 = fadd float %reg116, 3.000000e+01 ret float %reg117 } define float @test2_reassoc(float %reg109, float %reg1111) { ; CHECK-LABEL: @test2_reassoc( ; CHECK-NEXT: [[REG115:%.*]] = fadd reassoc float [[REG109:%.*]], -3.000000e+01 ; CHECK-NEXT: [[REG116:%.*]] = fadd reassoc float [[REG115]], [[REG1111:%.*]] ; CHECK-NEXT: [[REG117:%.*]] = fadd reassoc float [[REG116]], 3.000000e+01 ; CHECK-NEXT: ret float [[REG117]] ; %reg115 = fadd reassoc float %reg109, -3.000000e+01 %reg116 = fadd reassoc float %reg115, %reg1111 %reg117 = fadd reassoc float %reg116, 3.000000e+01 ret float %reg117 } @fe = external global float @fa = external global float @fb = external global float @fc = external global float @ff = external global float ; If two sums of the same operands in different order are counted with 'fast' ; flag and then stored to global variables, we can reuse the same value twice. ; Sums: ; - test3: (a+b)+c and (a+c)+b ; - test4: c+(a+b) and (c+a)+b ; - test5: c+(b+a) and (c+a)+b ; ; That only works with both gvn and reassociate passes enabled. ; Check that reassociate is not enough. define void @test3() { ; CHECK-LABEL: @test3( ; CHECK-NEXT: [[A:%.*]] = load float, float* @fa, align 4 ; CHECK-NEXT: [[B:%.*]] = load float, float* @fb, align 4 ; CHECK-NEXT: [[C:%.*]] = load float, float* @fc, align 4 ; CHECK-NEXT: [[T1:%.*]] = fadd fast float [[B]], [[A]] ; CHECK-NEXT: [[T2:%.*]] = fadd fast float [[T1]], [[C]] ; CHECK-NEXT: [[T3:%.*]] = fadd fast float [[B]], [[A]] ; CHECK-NEXT: [[T4:%.*]] = fadd fast float [[T3]], [[C]] ; CHECK-NEXT: store float [[T2]], float* @fe, align 4 ; CHECK-NEXT: store float [[T4]], float* @ff, align 4 ; CHECK-NEXT: ret void ; %A = load float, float* @fa %B = load float, float* @fb %C = load float, float* @fc %t1 = fadd fast float %A, %B %t2 = fadd fast float %t1, %C %t3 = fadd fast float %A, %C %t4 = fadd fast float %t3, %B ; e = (a+b)+c; store float %t2, float* @fe ; f = (a+c)+b store float %t4, float* @ff ret void } define void @test4() { ; CHECK-LABEL: @test4( ; CHECK-NEXT: [[A:%.*]] = load float, float* @fa, align 4 ; CHECK-NEXT: [[B:%.*]] = load float, float* @fb, align 4 ; CHECK-NEXT: [[C:%.*]] = load float, float* @fc, align 4 ; CHECK-NEXT: [[T1:%.*]] = fadd fast float [[B]], [[A]] ; CHECK-NEXT: [[T2:%.*]] = fadd fast float [[T1]], [[C]] ; CHECK-NEXT: [[T3:%.*]] = fadd fast float [[B]], [[A]] ; CHECK-NEXT: [[T4:%.*]] = fadd fast float [[T3]], [[C]] ; CHECK-NEXT: store float [[T2]], float* @fe, align 4 ; CHECK-NEXT: store float [[T4]], float* @ff, align 4 ; CHECK-NEXT: ret void ; %A = load float, float* @fa %B = load float, float* @fb %C = load float, float* @fc %t1 = fadd fast float %A, %B %t2 = fadd fast float %C, %t1 %t3 = fadd fast float %C, %A %t4 = fadd fast float %t3, %B ; e = c+(a+b) store float %t2, float* @fe ; f = (c+a)+b store float %t4, float* @ff ret void } define void @test5() { ; CHECK-LABEL: @test5( ; CHECK-NEXT: [[A:%.*]] = load float, float* @fa, align 4 ; CHECK-NEXT: [[B:%.*]] = load float, float* @fb, align 4 ; CHECK-NEXT: [[C:%.*]] = load float, float* @fc, align 4 ; CHECK-NEXT: [[T1:%.*]] = fadd fast float [[B]], [[A]] ; CHECK-NEXT: [[T2:%.*]] = fadd fast float [[T1]], [[C]] ; CHECK-NEXT: [[T3:%.*]] = fadd fast float [[B]], [[A]] ; CHECK-NEXT: [[T4:%.*]] = fadd fast float [[T3]], [[C]] ; CHECK-NEXT: store float [[T2]], float* @fe, align 4 ; CHECK-NEXT: store float [[T4]], float* @ff, align 4 ; CHECK-NEXT: ret void ; %A = load float, float* @fa %B = load float, float* @fb %C = load float, float* @fc %t1 = fadd fast float %B, %A %t2 = fadd fast float %C, %t1 %t3 = fadd fast float %C, %A %t4 = fadd fast float %t3, %B ; e = c+(b+a) store float %t2, float* @fe ; f = (c+a)+b store float %t4, float* @ff ret void } define float @test6(float %A, float %B, float %C) { ; CHECK-LABEL: @test6( ; CHECK-NEXT: [[REASS_ADD1:%.*]] = fadd fast float [[C:%.*]], [[B:%.*]] ; CHECK-NEXT: [[REASS_MUL2:%.*]] = fmul fast float [[A:%.*]], [[A]] ; CHECK-NEXT: [[REASS_MUL:%.*]] = fmul fast float [[REASS_MUL2]], [[REASS_ADD1]] ; CHECK-NEXT: ret float [[REASS_MUL]] ; %aa = fmul fast float %A, %A %aab = fmul fast float %aa, %B %ac = fmul fast float %A, %C %aac = fmul fast float %ac, %A %r = fadd fast float %aab, %aac ret float %r } define float @test6_reassoc(float %A, float %B, float %C) { ; CHECK-LABEL: @test6_reassoc( ; CHECK-NEXT: [[AA:%.*]] = fmul reassoc float [[A:%.*]], [[A]] ; CHECK-NEXT: [[AAB:%.*]] = fmul reassoc float [[AA]], [[B:%.*]] ; CHECK-NEXT: [[AC:%.*]] = fmul reassoc float [[A]], [[C:%.*]] ; CHECK-NEXT: [[AAC:%.*]] = fmul reassoc float [[A]], [[AC]] ; CHECK-NEXT: [[R:%.*]] = fadd reassoc float [[AAB]], [[AAC]] ; CHECK-NEXT: ret float [[R]] ; %aa = fmul reassoc float %A, %A %aab = fmul reassoc float %aa, %B %ac = fmul reassoc float %A, %C %aac = fmul reassoc float %ac, %A %r = fadd reassoc float %aab, %aac ret float %r } ; (-X)*Y + Z -> Z-X*Y define float @test7(float %X, float %Y, float %Z) { ; CHECK-LABEL: @test7( ; CHECK-NEXT: [[B:%.*]] = fmul fast float [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: [[TMP1:%.*]] = fsub fast float [[Z:%.*]], [[B]] ; CHECK-NEXT: ret float [[TMP1]] ; %A = fsub fast float 0.0, %X %B = fmul fast float %A, %Y %C = fadd fast float %B, %Z ret float %C } define float @test7_unary_fneg(float %X, float %Y, float %Z) { ; CHECK-LABEL: @test7_unary_fneg( ; CHECK-NEXT: [[B:%.*]] = fmul fast float [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: [[TMP1:%.*]] = fsub fast float [[Z:%.*]], [[B]] ; CHECK-NEXT: ret float [[TMP1]] ; %A = fneg fast float %X %B = fmul fast float %A, %Y %C = fadd fast float %B, %Z ret float %C } define float @test7_reassoc_nsz(float %X, float %Y, float %Z) { ; CHECK-LABEL: @test7_reassoc_nsz( ; CHECK-NEXT: [[B:%.*]] = fmul reassoc nsz float [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: [[TMP1:%.*]] = fsub reassoc nsz float [[Z:%.*]], [[B]] ; CHECK-NEXT: ret float [[TMP1]] ; %A = fsub reassoc nsz float 0.0, %X %B = fmul reassoc nsz float %A, %Y %C = fadd reassoc nsz float %B, %Z ret float %C } ; Verify that fold is not done only with 'reassoc' ('nsz' is required) define float @test7_reassoc(float %X, float %Y, float %Z) { ; CHECK-LABEL: @test7_reassoc( ; CHECK-NEXT: [[A:%.*]] = fsub reassoc float 0.000000e+00, [[X:%.*]] ; CHECK-NEXT: [[B:%.*]] = fmul reassoc float [[A]], [[Y:%.*]] ; CHECK-NEXT: [[C:%.*]] = fadd reassoc float [[B]], [[Z:%.*]] ; CHECK-NEXT: ret float [[C]] ; %A = fsub reassoc float 0.0, %X %B = fmul reassoc float %A, %Y %C = fadd reassoc float %B, %Z ret float %C } ; Integer version of: ; (-X)*Y + Z -> Z-X*Y ; TODO: check if we can change the mul of -1 and the add to a sub. define i32 @test7_int(i32 %X, i32 %Y, i32 %Z) { ; CHECK-LABEL: @test7_int( ; CHECK-NEXT: [[A:%.*]] = mul i32 [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: [[B:%.*]] = mul i32 [[A]], -1 ; CHECK-NEXT: [[C:%.*]] = add i32 [[B]], [[Z:%.*]] ; CHECK-NEXT: ret i32 [[C]] ; %A = sub i32 0, %X %B = mul i32 %A, %Y %C = add i32 %B, %Z ret i32 %C } define float @test8(float %X) { ; CHECK-LABEL: @test8( ; CHECK-NEXT: [[FACTOR:%.*]] = fmul fast float [[X:%.*]], 9.400000e+01 ; CHECK-NEXT: ret float [[FACTOR]] ; %Y = fmul fast float %X, 4.700000e+01 %Z = fadd fast float %Y, %Y ret float %Z } ; Side note: (x + x + x) and (3*x) each have only a single rounding. So ; transforming x+x+x to 3*x is always safe, even without any FMF. ; To avoid that special-case, we have the addition of 'x' four times, here. define float @test9(float %X) { ; CHECK-LABEL: @test9( ; CHECK-NEXT: [[FACTOR:%.*]] = fmul fast float [[X:%.*]], 4.000000e+00 ; CHECK-NEXT: ret float [[FACTOR]] ; %Y = fadd fast float %X ,%X %Z = fadd fast float %Y, %X %W = fadd fast float %Z, %X ret float %W } define float @test10(float %W) { ; CHECK-LABEL: @test10( ; CHECK-NEXT: [[FACTOR:%.*]] = fmul fast float [[W:%.*]], 3.810000e+02 ; CHECK-NEXT: ret float [[FACTOR]] ; %X = fmul fast float %W, 127.0 %Y = fadd fast float %X ,%X %Z = fadd fast float %Y, %X ret float %Z } define float @test11(float %X) { ; CHECK-LABEL: @test11( ; CHECK-NEXT: [[FACTOR:%.*]] = fmul fast float [[X:%.*]], -3.000000e+00 ; CHECK-NEXT: [[Z:%.*]] = fadd fast float [[FACTOR]], 6.000000e+00 ; CHECK-NEXT: ret float [[Z]] ; %A = fsub fast float 1.000000e+00, %X %B = fsub fast float 2.000000e+00, %X %C = fsub fast float 3.000000e+00, %X %Y = fadd fast float %A ,%B %Z = fadd fast float %Y, %C ret float %Z } define float @test12(float %X1, float %X2, float %X3) { ; CHECK-LABEL: @test12( ; CHECK-NEXT: [[B:%.*]] = fmul fast float [[X2:%.*]], [[X1:%.*]] ; CHECK-NEXT: [[C:%.*]] = fmul fast float [[X3:%.*]], [[X1]] ; CHECK-NEXT: [[TMP1:%.*]] = fsub fast float [[C]], [[B]] ; CHECK-NEXT: ret float [[TMP1]] ; %A = fsub fast float 0.000000e+00, %X1 %B = fmul fast float %A, %X2 ; -X1*X2 %C = fmul fast float %X1, %X3 ; X1*X3 %D = fadd fast float %B, %C ; -X1*X2 + X1*X3 -> X1*(X3-X2) ret float %D } define float @test12_unary_fneg(float %X1, float %X2, float %X3) { ; CHECK-LABEL: @test12_unary_fneg( ; CHECK-NEXT: [[B:%.*]] = fmul fast float [[X2:%.*]], [[X1:%.*]] ; CHECK-NEXT: [[C:%.*]] = fmul fast float [[X3:%.*]], [[X1]] ; CHECK-NEXT: [[TMP1:%.*]] = fsub fast float [[C]], [[B]] ; CHECK-NEXT: ret float [[TMP1]] ; %A = fneg fast float %X1 %B = fmul fast float %A, %X2 ; -X1*X2 %C = fmul fast float %X1, %X3 ; X1*X3 %D = fadd fast float %B, %C ; -X1*X2 + X1*X3 -> X1*(X3-X2) ret float %D } define float @test12_reassoc_nsz(float %X1, float %X2, float %X3) { ; CHECK-LABEL: @test12_reassoc_nsz( ; CHECK-NEXT: [[B:%.*]] = fmul reassoc nsz float [[X2:%.*]], [[X1:%.*]] ; CHECK-NEXT: [[C:%.*]] = fmul reassoc nsz float [[X3:%.*]], [[X1]] ; CHECK-NEXT: [[TMP1:%.*]] = fsub reassoc nsz float [[C]], [[B]] ; CHECK-NEXT: ret float [[TMP1]] ; %A = fsub reassoc nsz float 0.000000e+00, %X1 %B = fmul reassoc nsz float %A, %X2 ; -X1*X2 %C = fmul reassoc nsz float %X1, %X3 ; X1*X3 %D = fadd reassoc nsz float %B, %C ; -X1*X2 + X1*X3 -> X1*(X3-X2) ret float %D } ; TODO: check if 'nsz' is technically required. Currently the optimization ; is not done with only 'reassoc' without 'nsz'. define float @test12_reassoc(float %X1, float %X2, float %X3) { ; CHECK-LABEL: @test12_reassoc( ; CHECK-NEXT: [[A:%.*]] = fsub reassoc float 0.000000e+00, [[X1:%.*]] ; CHECK-NEXT: [[B:%.*]] = fmul reassoc float [[A]], [[X2:%.*]] ; CHECK-NEXT: [[C:%.*]] = fmul reassoc float [[X1]], [[X3:%.*]] ; CHECK-NEXT: [[D:%.*]] = fadd reassoc float [[B]], [[C]] ; CHECK-NEXT: ret float [[D]] ; %A = fsub reassoc float 0.000000e+00, %X1 %B = fmul reassoc float %A, %X2 ; -X1*X2 %C = fmul reassoc float %X1, %X3 ; X1*X3 %D = fadd reassoc float %B, %C ; -X1*X2 + X1*X3 -> X1*(X3-X2) ret float %D } ; (x1 * 47) + (x2 * -47) => (x1 - x2) * 47 ; That only works with both instcombine and reassociate passes enabled. ; Check that reassociate is not enough. define float @test13(float %X1, float %X2) { ; CHECK-LABEL: @test13( ; CHECK-NEXT: [[B:%.*]] = fmul fast float [[X1:%.*]], 4.700000e+01 ; CHECK-NEXT: [[C:%.*]] = fmul fast float [[X2:%.*]], 4.700000e+01 ; CHECK-NEXT: [[TMP1:%.*]] = fsub fast float [[B]], [[C]] ; CHECK-NEXT: ret float [[TMP1]] ; %B = fmul fast float %X1, 47. ; X1*47 %C = fmul fast float %X2, -47. ; X2*-47 %D = fadd fast float %B, %C ; X1*47 + X2*-47 -> 47*(X1-X2) ret float %D } define float @test13_reassoc_nsz(float %X1, float %X2) { ; CHECK-LABEL: @test13_reassoc_nsz( ; CHECK-NEXT: [[B:%.*]] = fmul reassoc nsz float [[X1:%.*]], 4.700000e+01 ; CHECK-NEXT: [[C:%.*]] = fmul reassoc nsz float [[X2:%.*]], 4.700000e+01 ; CHECK-NEXT: [[TMP1:%.*]] = fsub reassoc nsz float [[B]], [[C]] ; CHECK-NEXT: ret float [[TMP1]] ; %B = fmul reassoc nsz float %X1, 47. ; X1*47 %C = fmul reassoc nsz float %X2, -47. ; X2*-47 %D = fadd reassoc nsz float %B, %C ; X1*47 + X2*-47 -> 47*(X1-X2) ret float %D } define float @test13_reassoc(float %X1, float %X2) { ; CHECK-LABEL: @test13_reassoc( ; CHECK-NEXT: [[B:%.*]] = fmul reassoc float [[X1:%.*]], 4.700000e+01 ; CHECK-NEXT: [[C:%.*]] = fmul reassoc float [[X2:%.*]], 4.700000e+01 ; CHECK-NEXT: [[TMP1:%.*]] = fsub reassoc float [[B]], [[C]] ; CHECK-NEXT: ret float [[TMP1]] ; %B = fmul reassoc float %X1, 47. ; X1*47 %C = fmul reassoc float %X2, -47. ; X2*-47 %D = fadd reassoc float %B, %C ; X1*47 + X2*-47 -> 47*(X1-X2) ret float %D } define float @test14(float %arg) { ; CHECK-LABEL: @test14( ; CHECK-NEXT: [[T2:%.*]] = fmul fast float [[ARG:%.*]], 1.440000e+02 ; CHECK-NEXT: ret float [[T2]] ; %t1 = fmul fast float 1.200000e+01, %arg %t2 = fmul fast float %t1, 1.200000e+01 ret float %t2 } ; TODO: check if we can transform the code with 'reassoc' only. ; The same IR is transformed to one fmul in instcombine pass. define float @test14_reassoc(float %arg) { ; CHECK-LABEL: @test14_reassoc( ; CHECK-NEXT: [[T1:%.*]] = fmul reassoc float [[ARG:%.*]], 1.200000e+01 ; CHECK-NEXT: [[T2:%.*]] = fmul reassoc float [[T1]], 1.200000e+01 ; CHECK-NEXT: ret float [[T2]] ; %t1 = fmul reassoc float 1.200000e+01, %arg %t2 = fmul reassoc float %t1, 1.200000e+01 ret float %t2 } ; (b+(a+1234))+-a -> b+1234 ; That only works with both instcombine and reassociate passes enabled. ; Check that reassociate is not enough. ; TODO: check if we can remove dead fsub. define float @test15(float %b, float %a) { ; CHECK-LABEL: @test15( ; CHECK-NEXT: [[TMP1:%.*]] = fsub fast float 0.000000e+00, [[A:%.*]] ; CHECK-NEXT: [[TMP2:%.*]] = fadd fast float [[B:%.*]], 1.234000e+03 ; CHECK-NEXT: ret float [[TMP2]] ; %1 = fadd fast float %a, 1234.0 %2 = fadd fast float %b, %1 %3 = fsub fast float 0.0, %a %4 = fadd fast float %2, %3 ret float %4 } ; TODO: check if we can remove dead fneg. define float @test15_unary_fneg(float %b, float %a) { ; CHECK-LABEL: @test15_unary_fneg( ; CHECK-NEXT: [[TMP1:%.*]] = fneg fast float [[A:%.*]] ; CHECK-NEXT: [[TMP2:%.*]] = fadd fast float [[B:%.*]], 1.234000e+03 ; CHECK-NEXT: ret float [[TMP2]] ; %1 = fadd fast float %a, 1234.0 %2 = fadd fast float %b, %1 %3 = fneg fast float %a %4 = fadd fast float %2, %3 ret float %4 } ; TODO: check if we can remove dead fsub. define float @test15_reassoc_nsz(float %b, float %a) { ; CHECK-LABEL: @test15_reassoc_nsz( ; CHECK-NEXT: [[TMP1:%.*]] = fsub reassoc nsz float 0.000000e+00, [[A:%.*]] ; CHECK-NEXT: [[TMP2:%.*]] = fadd reassoc nsz float [[B:%.*]], 1.234000e+03 ; CHECK-NEXT: ret float [[TMP2]] ; %1 = fadd reassoc nsz float %a, 1234.0 %2 = fadd reassoc nsz float %b, %1 %3 = fsub reassoc nsz float 0.0, %a %4 = fadd reassoc nsz float %2, %3 ret float %4 } define float @test15_reassoc(float %b, float %a) { ; CHECK-LABEL: @test15_reassoc( ; CHECK-NEXT: [[TMP1:%.*]] = fadd reassoc float [[A:%.*]], 1.234000e+03 ; CHECK-NEXT: [[TMP2:%.*]] = fadd reassoc float [[B:%.*]], [[TMP1]] ; CHECK-NEXT: [[TMP3:%.*]] = fsub reassoc float 0.000000e+00, [[A]] ; CHECK-NEXT: [[TMP4:%.*]] = fadd reassoc float [[TMP3]], [[TMP2]] ; CHECK-NEXT: ret float [[TMP4]] ; %1 = fadd reassoc float %a, 1234.0 %2 = fadd reassoc float %b, %1 %3 = fsub reassoc float 0.0, %a %4 = fadd reassoc float %2, %3 ret float %4 } ; Test that we can turn things like X*-(Y*Z) -> X*-1*Y*Z. ; That only works with both instcombine and reassociate passes enabled. ; Check that reassociate is not enough. define float @test16(float %a, float %b, float %z) { ; CHECK-LABEL: @test16( ; CHECK-NEXT: [[C:%.*]] = fmul fast float [[A:%.*]], 1.234500e+04 ; CHECK-NEXT: [[E:%.*]] = fmul fast float [[C]], [[B:%.*]] ; CHECK-NEXT: [[F:%.*]] = fmul fast float [[E]], [[Z:%.*]] ; CHECK-NEXT: [[TMP1:%.*]] = fadd fast float [[F]], 0.000000e+00 ; CHECK-NEXT: ret float [[TMP1]] ; %c = fsub fast float 0.000000e+00, %z %d = fmul fast float %a, %b %e = fmul fast float %c, %d %f = fmul fast float %e, 1.234500e+04 %g = fsub fast float 0.000000e+00, %f ret float %g } define float @test16_unary_fneg(float %a, float %b, float %z) { ; CHECK-LABEL: @test16_unary_fneg( ; CHECK-NEXT: [[E:%.*]] = fmul fast float [[A:%.*]], 1.234500e+04 ; CHECK-NEXT: [[F:%.*]] = fmul fast float [[E]], [[B:%.*]] ; CHECK-NEXT: [[G:%.*]] = fmul fast float [[F]], [[Z:%.*]] ; CHECK-NEXT: ret float [[G]] ; %c = fneg fast float %z %d = fmul fast float %a, %b %e = fmul fast float %c, %d %f = fmul fast float %e, 1.234500e+04 %g = fneg fast float %f ret float %g } define float @test16_reassoc(float %a, float %b, float %z) { ; CHECK-LABEL: @test16_reassoc( ; CHECK-NEXT: [[C:%.*]] = fsub reassoc float 0.000000e+00, [[Z:%.*]] ; CHECK-NEXT: [[D:%.*]] = fmul reassoc float [[A:%.*]], [[B:%.*]] ; CHECK-NEXT: [[E:%.*]] = fmul reassoc float [[D]], [[C]] ; CHECK-NEXT: [[F:%.*]] = fmul reassoc float [[E]], 1.234500e+04 ; CHECK-NEXT: [[G:%.*]] = fsub reassoc float 0.000000e+00, [[F]] ; CHECK-NEXT: ret float [[G]] ; %c = fsub reassoc float 0.000000e+00, %z %d = fmul reassoc float %a, %b %e = fmul reassoc float %c, %d %f = fmul reassoc float %e, 1.234500e+04 %g = fsub reassoc float 0.000000e+00, %f ret float %g } ; TODO: check if we can remove: ; - fadd fast x, 0 ; ... as 'fast' implies 'nsz' define float @test17(float %a, float %b, float %z) { ; CHECK-LABEL: @test17( ; CHECK-NEXT: [[C:%.*]] = fmul fast float [[A:%.*]], 4.000000e+01 ; CHECK-NEXT: [[E:%.*]] = fmul fast float [[C]], [[Z:%.*]] ; CHECK-NEXT: [[TMP1:%.*]] = fadd fast float [[E]], 0.000000e+00 ; CHECK-NEXT: ret float [[TMP1]] ; %d = fmul fast float %z, 4.000000e+01 %c = fsub fast float 0.000000e+00, %d %e = fmul fast float %a, %c %f = fsub fast float 0.000000e+00, %e ret float %f } define float @test17_unary_fneg(float %a, float %b, float %z) { ; CHECK-LABEL: @test17_unary_fneg( ; CHECK-NEXT: [[E:%.*]] = fmul fast float [[A:%.*]], 4.000000e+01 ; CHECK-NEXT: [[F:%.*]] = fmul fast float [[E]], [[Z:%.*]] ; CHECK-NEXT: ret float [[F]] ; %d = fmul fast float %z, 4.000000e+01 %c = fneg fast float %d %e = fmul fast float %a, %c %f = fneg fast float %e ret float %f } ; With sub reassociation, constant folding can eliminate the 12 and -12 constants. ; TODO: check if we can remove fadd fast x, 0 as 'fast' implies 'nsz' define float @test18(float %A, float %B) { ; CHECK-LABEL: @test18( ; CHECK-NEXT: [[B_NEG:%.*]] = fneg fast float [[B:%.*]] ; CHECK-NEXT: [[Y:%.*]] = fadd fast float [[A:%.*]], 0.000000e+00 ; CHECK-NEXT: [[Z:%.*]] = fadd fast float [[Y]], [[B_NEG]] ; CHECK-NEXT: ret float [[Z]] ; %X = fadd fast float -1.200000e+01, %A %Y = fsub fast float %X, %B %Z = fadd fast float %Y, 1.200000e+01 ret float %Z }