1 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2 ; RUN: opt < %s -instcombine -S | FileCheck %s 3 4 ; PR4374 5 6 define 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 20 define 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 34 declare void @use(float) 35 declare void @use2(float, double) 36 37 define 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 52 define 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 65 define 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 78 define 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 91 define 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 } 99 100 define <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 } 108 109 define <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 119 120 define 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 } 129 130 define <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 } 139 140 define <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. 151 152 define 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. 165 166 define <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. 179 180 define 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. 193 194 define 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. 212 213 define 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. 229 230 define 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 1 249 250 define 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
