[llvm] [RISCV] Fold vfmv.f.s into load from stack (PR #110129)

[Craig Topper via llvm-commits]

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@@ -160,3 +160,103 @@ truebb:
 falsebb:
   ret i8 0
 }
+
+define double @f64(<vscale x 1 x double> %v, i1 %c) {
+; RV32-LABEL: f64:
+; RV32:       # %bb.0:
+; RV32-NEXT:    addi sp, sp, -16
+; RV32-NEXT:    .cfi_def_cfa_offset 16
+; RV32-NEXT:    csrr a1, vlenb
+; RV32-NEXT:    slli a1, a1, 1
+; RV32-NEXT:    sub sp, sp, a1
+; RV32-NEXT:    .cfi_escape 0x0f, 0x0d, 0x72, 0x00, 0x11, 0x10, 0x22, 0x11, 0x02, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # sp + 16 + 2 * vlenb
+; RV32-NEXT:    addi a1, sp, 16
+; RV32-NEXT:    vs1r.v v8, (a1) # Unknown-size Folded Spill
+; RV32-NEXT:    andi a0, a0, 1
+; RV32-NEXT:    #APP
+; RV32-NEXT:    #NO_APP
+; RV32-NEXT:    beqz a0, .LBB4_2
+; RV32-NEXT:  # %bb.1: # %truebb
+; RV32-NEXT:    addi a0, sp, 16
+; RV32-NEXT:    vl1r.v v8, (a0) # Unknown-size Folded Reload
+; RV32-NEXT:    vsetivli zero, 1, e64, m1, ta, ma
+; RV32-NEXT:    vfmv.f.s fa0, v8
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topperc wrote:

I guess it's the XLen check?

https://github.com/llvm/llvm-project/pull/110129