llvm-project

b9e133d5 - [AArch64][SVE] Use FeatureUseFixedOverScalableIfEqualCost for A320 (#152156)

[AArch64][SVE] Use FeatureUseFixedOverScalableIfEqualCost for A320 (#152156) With this new A320 in-order core, we follow adding the FeatureUseFixedOverScalableIfEqualCost feature to A510 and A520 (#132246), which reaps the same code generation benefits of preferring fixed over scalable when the cost is equal. So when we have: ``` void foo(float* a, float* b, float* dst, unsigned n) { for (unsigned i = 0; i < n; ++i) dst[i] = a[i] + b[i]; } ``` When compiling without the feature enabled, we get: ``` ... ld1b { z0.b }, p0/z, [x0, x10] ld1b { z2.b }, p0/z, [x1, x10] add x12, x0, x10 ldr z1, [x12, #1, mul vl] add x12, x1, x10 ldr z3, [x12, #1, mul vl] fadd z0.s, z2.s, z0.s add x12, x2, x10 fadd z1.s, z3.s, z1.s dech x11 st1b { z0.b }, p0, [x2, x10] incb x10, all, mul #2 str z1, [x12, #1, mul vl] ... ``` When compiling with, we get: ``` ... ldp q0, q1, [x12, #-16] ldp q2, q3, [x11, #-16] subs x13, x13, #8 fadd v0.4s, v2.4s, v0.4s fadd v1.4s, v3.4s, v1.4s add x11, x11, #32 add x12, x12, #32 stp q0, q1, [x10, #-16] add x10, x10, #32 ... ```