[llvm-branch-commits] [llvm] [RISCV] Add initial support of memcmp expansion (PR #107548)

[Craig Topper via llvm-branch-commits]

================
@@ -112,42 +104,46 @@ entry:
 define i32 @bcmp_size_2(ptr %s1, ptr %s2) nounwind optsize {
 ; CHECK-ALIGNED-RV32-LABEL: bcmp_size_2:
 ; CHECK-ALIGNED-RV32:       # %bb.0: # %entry
-; CHECK-ALIGNED-RV32-NEXT:    addi sp, sp, -16
-; CHECK-ALIGNED-RV32-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
-; CHECK-ALIGNED-RV32-NEXT:    li a2, 2
-; CHECK-ALIGNED-RV32-NEXT:    call bcmp
-; CHECK-ALIGNED-RV32-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
-; CHECK-ALIGNED-RV32-NEXT:    addi sp, sp, 16
+; CHECK-ALIGNED-RV32-NEXT:    lbu a2, 1(a0)
----------------
topperc wrote:

Would it be cheaper to Xor all the bytes individually and then Or the xor results together?

https://github.com/llvm/llvm-project/pull/107548