[llvm] [RISCV] Expand constant multiplication for targets without M extension (PR #137195)

[Craig Topper via llvm-commits]

================
@@ -882,6 +964,48 @@ define i64 @muli64_p72(i64 %a) nounwind {
 ;
 ; RV32IM-LABEL: muli64_p72:
 ; RV32IM:       # %bb.0:
+; RV32IM-NEXT:    li a2, 60
+; RV32IM-NEXT:    slli a3, a1, 2
+; RV32IM-NEXT:    slli a1, a1, 6
+; RV32IM-NEXT:    sub a1, a1, a3
+; RV32IM-NEXT:    slli a3, a0, 2
+; RV32IM-NEXT:    mulhu a2, a0, a2
+; RV32IM-NEXT:    slli a0, a0, 6
+; RV32IM-NEXT:    add a1, a2, a1
+; RV32IM-NEXT:    sub a0, a0, a3
+; RV32IM-NEXT:    ret
+;
+; RV64I-LABEL: muli64_p72:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a1, a0, 2
+; RV64I-NEXT:    slli a0, a0, 6
+; RV64I-NEXT:    sub a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64IM-LABEL: muli64_p72:
+; RV64IM:       # %bb.0:
+; RV64IM-NEXT:    slli a1, a0, 2
+; RV64IM-NEXT:    slli a0, a0, 6
+; RV64IM-NEXT:    sub a0, a0, a1
+; RV64IM-NEXT:    ret
+  %1 = mul i64 %a, 60
----------------
topperc wrote:

Test name says `p72` but the multiplier is 60

https://github.com/llvm/llvm-project/pull/137195