1 ; RUN: llc -mtriple=aarch64-gnu-linux -mcpu=cortex-a57 -enable-unsafe-fp-math -disable-post-ra < %s | FileCheck %s 2 3 ; Verify that the first two adds are independent regardless of how the inputs are 4 ; commuted. The destination registers are used as source registers for the third add. 5 6 define float @reassociate_adds1(float %x0, float %x1, float %x2, float %x3) { 7 ; CHECK-LABEL: reassociate_adds1: 8 ; CHECK: fadd s0, s0, s1 9 ; CHECK-NEXT: fadd s1, s2, s3 10 ; CHECK-NEXT: fadd s0, s0, s1 11 ; CHECK-NEXT: ret 12 %t0 = fadd float %x0, %x1 13 %t1 = fadd float %t0, %x2 14 %t2 = fadd float %t1, %x3 15 ret float %t2 16 } 17 18 define float @reassociate_adds2(float %x0, float %x1, float %x2, float %x3) { 19 ; CHECK-LABEL: reassociate_adds2: 20 ; CHECK: fadd s0, s0, s1 21 ; CHECK-NEXT: fadd s1, s2, s3 22 ; CHECK-NEXT: fadd s0, s0, s1 23 ; CHECK-NEXT: ret 24 %t0 = fadd float %x0, %x1 25 %t1 = fadd float %x2, %t0 26 %t2 = fadd float %t1, %x3 27 ret float %t2 28 } 29 30 define float @reassociate_adds3(float %x0, float %x1, float %x2, float %x3) { 31 ; CHECK-LABEL: reassociate_adds3: 32 ; CHECK: s0, s0, s1 33 ; CHECK-NEXT: s1, s2, s3 34 ; CHECK-NEXT: s0, s0, s1 35 ; CHECK-NEXT: ret 36 %t0 = fadd float %x0, %x1 37 %t1 = fadd float %t0, %x2 38 %t2 = fadd float %x3, %t1 39 ret float %t2 40 } 41 42 define float @reassociate_adds4(float %x0, float %x1, float %x2, float %x3) { 43 ; CHECK-LABEL: reassociate_adds4: 44 ; CHECK: s0, s0, s1 45 ; CHECK-NEXT: s1, s2, s3 46 ; CHECK-NEXT: s0, s0, s1 47 ; CHECK-NEXT: ret 48 %t0 = fadd float %x0, %x1 49 %t1 = fadd float %x2, %t0 50 %t2 = fadd float %x3, %t1 51 ret float %t2 52 } 53 54 ; Verify that we reassociate some of these ops. The optimal balanced tree of adds is not 55 ; produced because that would cost more compile time. 56 57 define float @reassociate_adds5(float %x0, float %x1, float %x2, float %x3, float %x4, float %x5, float %x6, float %x7) { 58 ; CHECK-LABEL: reassociate_adds5: 59 ; CHECK: fadd s0, s0, s1 60 ; CHECK-NEXT: fadd s1, s2, s3 61 ; CHECK-NEXT: fadd s0, s0, s1 62 ; CHECK-NEXT: fadd s1, s4, s5 63 ; CHECK-NEXT: fadd s1, s1, s6 64 ; CHECK-NEXT: fadd s0, s0, s1 65 ; CHECK-NEXT: fadd s0, s0, s7 66 ; CHECK-NEXT: ret 67 %t0 = fadd float %x0, %x1 68 %t1 = fadd float %t0, %x2 69 %t2 = fadd float %t1, %x3 70 %t3 = fadd float %t2, %x4 71 %t4 = fadd float %t3, %x5 72 %t5 = fadd float %t4, %x6 73 %t6 = fadd float %t5, %x7 74 ret float %t6 75 } 76 77 ; Verify that we only need two associative operations to reassociate the operands. 78 ; Also, we should reassociate such that the result of the high latency division 79 ; is used by the final 'add' rather than reassociating the %x3 operand with the 80 ; division. The latter reassociation would not improve anything. 81 82 define float @reassociate_adds6(float %x0, float %x1, float %x2, float %x3) { 83 ; CHECK-LABEL: reassociate_adds6: 84 ; CHECK: fdiv s0, s0, s1 85 ; CHECK-NEXT: fadd s1, s2, s3 86 ; CHECK-NEXT: fadd s0, s0, s1 87 ; CHECK-NEXT: ret 88 %t0 = fdiv float %x0, %x1 89 %t1 = fadd float %x2, %t0 90 %t2 = fadd float %x3, %t1 91 ret float %t2 92 } 93 94 ; Verify that scalar single-precision multiplies are reassociated. 95 96 define float @reassociate_muls1(float %x0, float %x1, float %x2, float %x3) { 97 ; CHECK-LABEL: reassociate_muls1: 98 ; CHECK: fdiv s0, s0, s1 99 ; CHECK-NEXT: fmul s1, s2, s3 100 ; CHECK-NEXT: fmul s0, s0, s1 101 ; CHECK-NEXT: ret 102 %t0 = fdiv float %x0, %x1 103 %t1 = fmul float %x2, %t0 104 %t2 = fmul float %x3, %t1 105 ret float %t2 106 } 107 108 ; Verify that scalar double-precision adds are reassociated. 109 110 define double @reassociate_adds_double(double %x0, double %x1, double %x2, double %x3) { 111 ; CHECK-LABEL: reassociate_adds_double: 112 ; CHECK: fdiv d0, d0, d1 113 ; CHECK-NEXT: fadd d1, d2, d3 114 ; CHECK-NEXT: fadd d0, d0, d1 115 ; CHECK-NEXT: ret 116 %t0 = fdiv double %x0, %x1 117 %t1 = fadd double %x2, %t0 118 %t2 = fadd double %x3, %t1 119 ret double %t2 120 } 121 122 ; Verify that scalar double-precision multiplies are reassociated. 123 124 define double @reassociate_muls_double(double %x0, double %x1, double %x2, double %x3) { 125 ; CHECK-LABEL: reassociate_muls_double: 126 ; CHECK: fdiv d0, d0, d1 127 ; CHECK-NEXT: fmul d1, d2, d3 128 ; CHECK-NEXT: fmul d0, d0, d1 129 ; CHECK-NEXT: ret 130 %t0 = fdiv double %x0, %x1 131 %t1 = fmul double %x2, %t0 132 %t2 = fmul double %x3, %t1 133 ret double %t2 134 } 135 136 ; Verify that we reassociate vector instructions too. 137 138 define <4 x float> @vector_reassociate_adds1(<4 x float> %x0, <4 x float> %x1, <4 x float> %x2, <4 x float> %x3) { 139 ; CHECK-LABEL: vector_reassociate_adds1: 140 ; CHECK: fadd v0.4s, v0.4s, v1.4s 141 ; CHECK-NEXT: fadd v1.4s, v2.4s, v3.4s 142 ; CHECK-NEXT: fadd v0.4s, v0.4s, v1.4s 143 ; CHECK-NEXT: ret 144 %t0 = fadd <4 x float> %x0, %x1 145 %t1 = fadd <4 x float> %t0, %x2 146 %t2 = fadd <4 x float> %t1, %x3 147 ret <4 x float> %t2 148 } 149 150 define <4 x float> @vector_reassociate_adds2(<4 x float> %x0, <4 x float> %x1, <4 x float> %x2, <4 x float> %x3) { 151 ; CHECK-LABEL: vector_reassociate_adds2: 152 ; CHECK: fadd v0.4s, v0.4s, v1.4s 153 ; CHECK-NEXT: fadd v1.4s, v2.4s, v3.4s 154 ; CHECK-NEXT: fadd v0.4s, v0.4s, v1.4s 155 %t0 = fadd <4 x float> %x0, %x1 156 %t1 = fadd <4 x float> %x2, %t0 157 %t2 = fadd <4 x float> %t1, %x3 158 ret <4 x float> %t2 159 } 160 161 define <4 x float> @vector_reassociate_adds3(<4 x float> %x0, <4 x float> %x1, <4 x float> %x2, <4 x float> %x3) { 162 ; CHECK-LABEL: vector_reassociate_adds3: 163 ; CHECK: fadd v0.4s, v0.4s, v1.4s 164 ; CHECK-NEXT: fadd v1.4s, v2.4s, v3.4s 165 ; CHECK-NEXT: fadd v0.4s, v0.4s, v1.4s 166 %t0 = fadd <4 x float> %x0, %x1 167 %t1 = fadd <4 x float> %t0, %x2 168 %t2 = fadd <4 x float> %x3, %t1 169 ret <4 x float> %t2 170 } 171 172 define <4 x float> @vector_reassociate_adds4(<4 x float> %x0, <4 x float> %x1, <4 x float> %x2, <4 x float> %x3) { 173 ; CHECK-LABEL: vector_reassociate_adds4: 174 ; CHECK: fadd v0.4s, v0.4s, v1.4s 175 ; CHECK-NEXT: fadd v1.4s, v2.4s, v3.4s 176 ; CHECK-NEXT: fadd v0.4s, v0.4s, v1.4s 177 %t0 = fadd <4 x float> %x0, %x1 178 %t1 = fadd <4 x float> %x2, %t0 179 %t2 = fadd <4 x float> %x3, %t1 180 ret <4 x float> %t2 181 } 182 ; Verify that 128-bit vector single-precision multiplies are reassociated. 183 184 define <4 x float> @reassociate_muls_v4f32(<4 x float> %x0, <4 x float> %x1, <4 x float> %x2, <4 x float> %x3) { 185 ; CHECK-LABEL: reassociate_muls_v4f32: 186 ; CHECK: fadd v0.4s, v0.4s, v1.4s 187 ; CHECK-NEXT: fmul v1.4s, v2.4s, v3.4s 188 ; CHECK-NEXT: fmul v0.4s, v0.4s, v1.4s 189 ; CHECK-NEXT: ret 190 %t0 = fadd <4 x float> %x0, %x1 191 %t1 = fmul <4 x float> %x2, %t0 192 %t2 = fmul <4 x float> %x3, %t1 193 ret <4 x float> %t2 194 } 195 196 ; Verify that 128-bit vector double-precision multiplies are reassociated. 197 198 define <2 x double> @reassociate_muls_v2f64(<2 x double> %x0, <2 x double> %x1, <2 x double> %x2, <2 x double> %x3) { 199 ; CHECK-LABEL: reassociate_muls_v2f64: 200 ; CHECK: fadd v0.2d, v0.2d, v1.2d 201 ; CHECK-NEXT: fmul v1.2d, v2.2d, v3.2d 202 ; CHECK-NEXT: fmul v0.2d, v0.2d, v1.2d 203 ; CHECK-NEXT: ret 204 %t0 = fadd <2 x double> %x0, %x1 205 %t1 = fmul <2 x double> %x2, %t0 206 %t2 = fmul <2 x double> %x3, %t1 207 ret <2 x double> %t2 208 } 209 210 ; PR25016: https://llvm.org/bugs/show_bug.cgi?id=25016 211 ; Verify that reassociation is not happening needlessly or wrongly. 212 213 declare double @bar() 214 215 define double @reassociate_adds_from_calls() { 216 ; CHECK-LABEL: reassociate_adds_from_calls: 217 ; CHECK: bl bar 218 ; CHECK-NEXT: mov v8.16b, v0.16b 219 ; CHECK-NEXT: bl bar 220 ; CHECK-NEXT: mov v9.16b, v0.16b 221 ; CHECK-NEXT: bl bar 222 ; CHECK-NEXT: mov v10.16b, v0.16b 223 ; CHECK-NEXT: bl bar 224 ; CHECK: fadd d1, d8, d9 225 ; CHECK-NEXT: fadd d0, d10, d0 226 ; CHECK-NEXT: fadd d0, d1, d0 227 %x0 = call double @bar() 228 %x1 = call double @bar() 229 %x2 = call double @bar() 230 %x3 = call double @bar() 231 %t0 = fadd double %x0, %x1 232 %t1 = fadd double %t0, %x2 233 %t2 = fadd double %t1, %x3 234 ret double %t2 235 } 236 237 define double @already_reassociated() { 238 ; CHECK-LABEL: already_reassociated: 239 ; CHECK: bl bar 240 ; CHECK-NEXT: mov v8.16b, v0.16b 241 ; CHECK-NEXT: bl bar 242 ; CHECK-NEXT: mov v9.16b, v0.16b 243 ; CHECK-NEXT: bl bar 244 ; CHECK-NEXT: mov v10.16b, v0.16b 245 ; CHECK-NEXT: bl bar 246 ; CHECK: fadd d1, d8, d9 247 ; CHECK-NEXT: fadd d0, d10, d0 248 ; CHECK-NEXT: fadd d0, d1, d0 249 %x0 = call double @bar() 250 %x1 = call double @bar() 251 %x2 = call double @bar() 252 %x3 = call double @bar() 253 %t0 = fadd double %x0, %x1 254 %t1 = fadd double %x2, %x3 255 %t2 = fadd double %t0, %t1 256 ret double %t2 257 } 258 259
