1 ; RUN: llc -mtriple=aarch64-gnu-linux -mcpu=cortex-a57 -enable-unsafe-fp-math -disable-post-ra < %s | FileCheck %s
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.
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
12 %t0 = fadd float %x0, %x1
13 %t1 = fadd float %t0, %x2
14 %t2 = fadd float %t1, %x3
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
24 %t0 = fadd float %x0, %x1
25 %t1 = fadd float %x2, %t0
26 %t2 = fadd float %t1, %x3
30 define float @reassociate_adds3(float %x0, float %x1, float %x2, float %x3) {
31 ; CHECK-LABEL: reassociate_adds3:
33 ; CHECK-NEXT: s1, s2, s3
34 ; CHECK-NEXT: s0, s0, s1
36 %t0 = fadd float %x0, %x1
37 %t1 = fadd float %t0, %x2
38 %t2 = fadd float %x3, %t1
42 define float @reassociate_adds4(float %x0, float %x1, float %x2, float %x3) {
43 ; CHECK-LABEL: reassociate_adds4:
45 ; CHECK-NEXT: s1, s2, s3
46 ; CHECK-NEXT: s0, s0, s1
48 %t0 = fadd float %x0, %x1
49 %t1 = fadd float %x2, %t0
50 %t2 = fadd float %x3, %t1
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.
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
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
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.
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
88 %t0 = fdiv float %x0, %x1
89 %t1 = fadd float %x2, %t0
90 %t2 = fadd float %x3, %t1
94 ; Verify that scalar single-precision multiplies are reassociated.
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
102 %t0 = fdiv float %x0, %x1
103 %t1 = fmul float %x2, %t0
104 %t2 = fmul float %x3, %t1
108 ; Verify that scalar double-precision adds are reassociated.
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
116 %t0 = fdiv double %x0, %x1
117 %t1 = fadd double %x2, %t0
118 %t2 = fadd double %x3, %t1
122 ; Verify that scalar double-precision multiplies are reassociated.
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
130 %t0 = fdiv double %x0, %x1
131 %t1 = fmul double %x2, %t0
132 %t2 = fmul double %x3, %t1
136 ; Verify that we reassociate vector instructions too.
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
144 %t0 = fadd <4 x float> %x0, %x1
145 %t1 = fadd <4 x float> %t0, %x2
146 %t2 = fadd <4 x float> %t1, %x3
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
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
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
182 ; Verify that 128-bit vector single-precision multiplies are reassociated.
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
190 %t0 = fadd <4 x float> %x0, %x1
191 %t1 = fmul <4 x float> %x2, %t0
192 %t2 = fmul <4 x float> %x3, %t1
196 ; Verify that 128-bit vector double-precision multiplies are reassociated.
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
204 %t0 = fadd <2 x double> %x0, %x1
205 %t1 = fmul <2 x double> %x2, %t0
206 %t2 = fmul <2 x double> %x3, %t1
210 ; PR25016: https://llvm.org/bugs/show_bug.cgi?id=25016
211 ; Verify that reassociation is not happening needlessly or wrongly.
213 declare double @bar()
215 define double @reassociate_adds_from_calls() {
216 ; CHECK-LABEL: reassociate_adds_from_calls:
218 ; CHECK-NEXT: mov v8.16b, v0.16b
220 ; CHECK-NEXT: mov v9.16b, v0.16b
222 ; CHECK-NEXT: mov v10.16b, v0.16b
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
237 define double @already_reassociated() {
238 ; CHECK-LABEL: already_reassociated:
240 ; CHECK-NEXT: mov v8.16b, v0.16b
242 ; CHECK-NEXT: mov v9.16b, v0.16b
244 ; CHECK-NEXT: mov v10.16b, v0.16b
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