[llvm] [RISCV] Prefer SP over FP for frame index access when offset fits within compressed immediate range. (PR #193962)

[Craig Topper via llvm-commits]

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@@ -153,7 +153,7 @@ define void @frame_pointer() "frame-pointer"="all" {
 ; RV64I-NEXT:    addi s0, sp, 2032
 ; RV64I-NEXT:    .cfi_def_cfa s0, 0
 ; RV64I-NEXT:    addi sp, sp, -496
-; RV64I-NEXT:    addi a0, s0, -1972
+; RV64I-NEXT:    addi a0, sp, 556
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topperc wrote:

I believe this is because we need to teach RISCVRegisterInfo::needsFrameBaseReg about this patch. I think we can do that as a follow up.

https://github.com/llvm/llvm-project/pull/193962