1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; RUN: opt < %s -instcombine -S | FileCheck %s 3 4; PR4374 5 6define float @test1(float %x, float %y) { 7; CHECK-LABEL: @test1( 8; CHECK-NEXT: [[T1:%.*]] = fsub float [[X:%.*]], [[Y:%.*]] 9; CHECK-NEXT: [[T2:%.*]] = fsub float -0.000000e+00, [[T1]] 10; CHECK-NEXT: ret float [[T2]] 11; 12 %t1 = fsub float %x, %y 13 %t2 = fsub float -0.0, %t1 14 ret float %t2 15} 16 17; Can't do anything with the test above because -0.0 - 0.0 = -0.0, but if we have nsz: 18; -(X - Y) --> Y - X 19 20define float @neg_sub_nsz(float %x, float %y) { 21; CHECK-LABEL: @neg_sub_nsz( 22; CHECK-NEXT: [[TMP1:%.*]] = fsub nsz float [[Y:%.*]], [[X:%.*]] 23; CHECK-NEXT: ret float [[TMP1]] 24; 25 %t1 = fsub float %x, %y 26 %t2 = fsub nsz float -0.0, %t1 27 ret float %t2 28} 29 30; If the subtract has another use, we don't do the transform (even though it 31; doesn't increase the IR instruction count) because we assume that fneg is 32; easier to analyze and generally cheaper than generic fsub. 33 34declare void @use(float) 35declare void @use2(float, double) 36 37define float @neg_sub_nsz_extra_use(float %x, float %y) { 38; CHECK-LABEL: @neg_sub_nsz_extra_use( 39; CHECK-NEXT: [[T1:%.*]] = fsub float [[X:%.*]], [[Y:%.*]] 40; CHECK-NEXT: [[T2:%.*]] = fsub nsz float -0.000000e+00, [[T1]] 41; CHECK-NEXT: call void @use(float [[T1]]) 42; CHECK-NEXT: ret float [[T2]] 43; 44 %t1 = fsub float %x, %y 45 %t2 = fsub nsz float -0.0, %t1 46 call void @use(float %t1) 47 ret float %t2 48} 49 50; With nsz: Z - (X - Y) --> Z + (Y - X) 51 52define float @sub_sub_nsz(float %x, float %y, float %z) { 53; CHECK-LABEL: @sub_sub_nsz( 54; CHECK-NEXT: [[TMP1:%.*]] = fsub nsz float [[Y:%.*]], [[X:%.*]] 55; CHECK-NEXT: [[T2:%.*]] = fadd nsz float [[TMP1]], [[Z:%.*]] 56; CHECK-NEXT: ret float [[T2]] 57; 58 %t1 = fsub float %x, %y 59 %t2 = fsub nsz float %z, %t1 60 ret float %t2 61} 62 63; Same as above: if 'Z' is not -0.0, swap fsub operands and convert to fadd. 64 65define float @sub_sub_known_not_negzero(float %x, float %y) { 66; CHECK-LABEL: @sub_sub_known_not_negzero( 67; CHECK-NEXT: [[TMP1:%.*]] = fsub float [[Y:%.*]], [[X:%.*]] 68; CHECK-NEXT: [[T2:%.*]] = fadd float [[TMP1]], 4.200000e+01 69; CHECK-NEXT: ret float [[T2]] 70; 71 %t1 = fsub float %x, %y 72 %t2 = fsub float 42.0, %t1 73 ret float %t2 74} 75 76; <rdar://problem/7530098> 77 78define double @test2(double %x, double %y) { 79; CHECK-LABEL: @test2( 80; CHECK-NEXT: [[T1:%.*]] = fadd double [[X:%.*]], [[Y:%.*]] 81; CHECK-NEXT: [[T2:%.*]] = fsub double [[X]], [[T1]] 82; CHECK-NEXT: ret double [[T2]] 83; 84 %t1 = fadd double %x, %y 85 %t2 = fsub double %x, %t1 86 ret double %t2 87} 88 89; X - C --> X + (-C) 90 91define float @constant_op1(float %x, float %y) { 92; CHECK-LABEL: @constant_op1( 93; CHECK-NEXT: [[R:%.*]] = fadd float [[X:%.*]], -4.200000e+01 94; CHECK-NEXT: ret float [[R]] 95; 96 %r = fsub float %x, 42.0 97 ret float %r 98} 99 100define <2 x float> @constant_op1_vec(<2 x float> %x, <2 x float> %y) { 101; CHECK-LABEL: @constant_op1_vec( 102; CHECK-NEXT: [[R:%.*]] = fadd <2 x float> [[X:%.*]], <float -4.200000e+01, float 4.200000e+01> 103; CHECK-NEXT: ret <2 x float> [[R]] 104; 105 %r = fsub <2 x float> %x, <float 42.0, float -42.0> 106 ret <2 x float> %r 107} 108 109define <2 x float> @constant_op1_vec_undef(<2 x float> %x, <2 x float> %y) { 110; CHECK-LABEL: @constant_op1_vec_undef( 111; CHECK-NEXT: [[R:%.*]] = fadd <2 x float> [[X:%.*]], <float 0x7FF8000000000000, float 4.200000e+01> 112; CHECK-NEXT: ret <2 x float> [[R]] 113; 114 %r = fsub <2 x float> %x, <float undef, float -42.0> 115 ret <2 x float> %r 116} 117 118; X - (-Y) --> X + Y 119 120define float @neg_op1(float %x, float %y) { 121; CHECK-LABEL: @neg_op1( 122; CHECK-NEXT: [[R:%.*]] = fadd float [[X:%.*]], [[Y:%.*]] 123; CHECK-NEXT: ret float [[R]] 124; 125 %negy = fsub float -0.0, %y 126 %r = fsub float %x, %negy 127 ret float %r 128} 129 130define <2 x float> @neg_op1_vec(<2 x float> %x, <2 x float> %y) { 131; CHECK-LABEL: @neg_op1_vec( 132; CHECK-NEXT: [[R:%.*]] = fadd <2 x float> [[X:%.*]], [[Y:%.*]] 133; CHECK-NEXT: ret <2 x float> [[R]] 134; 135 %negy = fsub <2 x float> <float -0.0, float -0.0>, %y 136 %r = fsub <2 x float> %x, %negy 137 ret <2 x float> %r 138} 139 140define <2 x float> @neg_op1_vec_undef(<2 x float> %x, <2 x float> %y) { 141; CHECK-LABEL: @neg_op1_vec_undef( 142; CHECK-NEXT: [[R:%.*]] = fadd <2 x float> [[X:%.*]], [[Y:%.*]] 143; CHECK-NEXT: ret <2 x float> [[R]] 144; 145 %negy = fsub <2 x float> <float -0.0, float undef>, %y 146 %r = fsub <2 x float> %x, %negy 147 ret <2 x float> %r 148} 149 150; Similar to above - but look through fpext/fptrunc casts to find the fneg. 151 152define double @neg_ext_op1(float %a, double %b) { 153; CHECK-LABEL: @neg_ext_op1( 154; CHECK-NEXT: [[TMP1:%.*]] = fpext float [[A:%.*]] to double 155; CHECK-NEXT: [[T3:%.*]] = fadd double [[TMP1]], [[B:%.*]] 156; CHECK-NEXT: ret double [[T3]] 157; 158 %t1 = fsub float -0.0, %a 159 %t2 = fpext float %t1 to double 160 %t3 = fsub double %b, %t2 161 ret double %t3 162} 163 164; Verify that vectors work too. 165 166define <2 x float> @neg_trunc_op1(<2 x double> %a, <2 x float> %b) { 167; CHECK-LABEL: @neg_trunc_op1( 168; CHECK-NEXT: [[TMP1:%.*]] = fptrunc <2 x double> [[A:%.*]] to <2 x float> 169; CHECK-NEXT: [[T3:%.*]] = fadd <2 x float> [[TMP1]], [[B:%.*]] 170; CHECK-NEXT: ret <2 x float> [[T3]] 171; 172 %t1 = fsub <2 x double> <double -0.0, double -0.0>, %a 173 %t2 = fptrunc <2 x double> %t1 to <2 x float> 174 %t3 = fsub <2 x float> %b, %t2 175 ret <2 x float> %t3 176} 177 178; No FMF needed, but they should propagate to the fadd. 179 180define double @neg_ext_op1_fast(float %a, double %b) { 181; CHECK-LABEL: @neg_ext_op1_fast( 182; CHECK-NEXT: [[TMP1:%.*]] = fpext float [[A:%.*]] to double 183; CHECK-NEXT: [[T3:%.*]] = fadd fast double [[TMP1]], [[B:%.*]] 184; CHECK-NEXT: ret double [[T3]] 185; 186 %t1 = fsub float -0.0, %a 187 %t2 = fpext float %t1 to double 188 %t3 = fsub fast double %b, %t2 189 ret double %t3 190} 191 192; Extra use should prevent the transform. 193 194define float @neg_ext_op1_extra_use(half %a, float %b) { 195; CHECK-LABEL: @neg_ext_op1_extra_use( 196; CHECK-NEXT: [[T1:%.*]] = fsub half 0xH8000, [[A:%.*]] 197; CHECK-NEXT: [[T2:%.*]] = fpext half [[T1]] to float 198; CHECK-NEXT: [[T3:%.*]] = fsub float [[B:%.*]], [[T2]] 199; CHECK-NEXT: call void @use(float [[T2]]) 200; CHECK-NEXT: ret float [[T3]] 201; 202 %t1 = fsub half -0.0, %a 203 %t2 = fpext half %t1 to float 204 %t3 = fsub float %b, %t2 205 call void @use(float %t2) 206 ret float %t3 207} 208 209; One-use fptrunc is always hoisted above fneg, so the corresponding 210; multi-use bug for fptrunc isn't visible with a fold starting from 211; the last fsub. 212 213define float @neg_trunc_op1_extra_use(double %a, float %b) { 214; CHECK-LABEL: @neg_trunc_op1_extra_use( 215; CHECK-NEXT: [[TMP1:%.*]] = fptrunc double [[A:%.*]] to float 216; CHECK-NEXT: [[T2:%.*]] = fsub float -0.000000e+00, [[TMP1]] 217; CHECK-NEXT: [[T3:%.*]] = fadd float [[TMP1]], [[B:%.*]] 218; CHECK-NEXT: call void @use(float [[T2]]) 219; CHECK-NEXT: ret float [[T3]] 220; 221 %t1 = fsub double -0.0, %a 222 %t2 = fptrunc double %t1 to float 223 %t3 = fsub float %b, %t2 224 call void @use(float %t2) 225 ret float %t3 226} 227 228; Extra uses should prevent the transform. 229 230define float @neg_trunc_op1_extra_uses(double %a, float %b) { 231; CHECK-LABEL: @neg_trunc_op1_extra_uses( 232; CHECK-NEXT: [[T1:%.*]] = fsub double -0.000000e+00, [[A:%.*]] 233; CHECK-NEXT: [[T2:%.*]] = fptrunc double [[T1]] to float 234; CHECK-NEXT: [[T3:%.*]] = fsub float [[B:%.*]], [[T2]] 235; CHECK-NEXT: call void @use2(float [[T2]], double [[T1]]) 236; CHECK-NEXT: ret float [[T3]] 237; 238 %t1 = fsub double -0.0, %a 239 %t2 = fptrunc double %t1 to float 240 %t3 = fsub float %b, %t2 241 call void @use2(float %t2, double %t1) 242 ret float %t3 243} 244 245; Don't negate a constant expression to form fadd and induce infinite looping: 246; https://bugs.llvm.org/show_bug.cgi?id=37605 247 248@b = external global i16, align 1 249 250define float @PR37605(float %conv) { 251; CHECK-LABEL: @PR37605( 252; CHECK-NEXT: [[SUB:%.*]] = fsub float [[CONV:%.*]], bitcast (i32 ptrtoint (i16* @b to i32) to float) 253; CHECK-NEXT: ret float [[SUB]] 254; 255 %sub = fsub float %conv, bitcast (i32 ptrtoint (i16* @b to i32) to float) 256 ret float %sub 257} 258 259