fallback: legalize: G_XOR <2 x s16>

Run:main-bc8218b282-20261015-074651
Kind:fallback
Category:legalize: G_XOR <2 x s16> NEW
Occurrences:2 in 2 configs, 2 test files
Snippet from:rvp-mul-parts-acc-fold.4be1cee1a1.ll (mutant of rvp-mul-parts-acc-fold.ll) @macc_h11 via llvm-extract
Config:-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs
Local check:reproduces at bc8218b282
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

define i32 @macc_h11(i32 %rd, <2 x i16> %a, <2 x i16> %b) {
  %A = alloca <2 x i16>, align 4
  store <2 x i16> poison, ptr %A, align 4
  %m = call i32 @llvm.riscv.mul.11.i32.v2i16(<2 x i16> %a, <2 x i16> %b)
  %r = add i32 %rd, %m
  %B = xor <2 x i16> %a, %b
  store <2 x i16> %B, ptr %A, align 4
  ret i32 %r
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.riscv.mul.11.i32.v2i16(<2 x i16>, <2 x i16>) #0

attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

Reproduce:

llc -mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %12:_(<2 x s16>) = G_XOR %1:_, %2:_ (in function: macc_h11)
warning: Instruction selection used fallback path for macc_h11

Occurrences (2):

InputFunctionConfig
rvp-mul-parts-acc-fold.4be1cee1a1.ll (mutant of rvp-mul-parts-acc-fold.ll)macc_h11-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs
rvp-simd-32.cddd1509ff.ll (mutant of rvp-simd-32.ll)test_pdif_h-mtriple=riscv32 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs

Generated 2026-10-15 08:05 UTC.