fallback: legalize: G_OR <4 x s32>

Run:explore-bc8218b282-20261015-075519
Kind:fallback
Category:legalize: G_OR <4 x s32>
Occurrences:1 in 1 configs, 1 test files
Snippet from:combine-is_fpclass.ll @extract_bitcast_oob_idx via llvm-extract
Config:-mtriple=riscv64 -mattr=+v,+f,+d
Local check:reproduces at bc8218b282
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define i1 @extract_bitcast_oob_idx(<4 x i32> %bits, ptr %p) #0 {
  %masked = or <4 x i32> %bits, <i32 -2147483648, i32 0, i32 -2147483648, i32 0>
  %fvec = bitcast <4 x i32> %masked to <4 x float>
  store <4 x float> %fvec, ptr %p, align 16
  %elt = extractelement <4 x float> %fvec, i32 6
  %res = call i1 @llvm.is.fpclass.f32(float %elt, /* (nan) */ i32 3)
  ret i1 %res
}

; Function Attrs: nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none)
declare i1 @llvm.is.fpclass.f32(float, i32 immarg) #1

attributes #0 = { nounwind }
attributes #1 = { nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none) }

Reproduce:

llc -mtriple=riscv64 -mattr=+v,+f,+d -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+v,+f,+d -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %6:_(<4 x s32>) = G_OR %0:_, %3:_ (in function: extract_bitcast_oob_idx)
warning: Instruction selection used fallback path for extract_bitcast_oob_idx

Occurrences (1):

InputFunctionConfig
combine-is_fpclass.llextract_bitcast_oob_idx-mtriple=riscv64 -mattr=+v,+f,+d

Generated 2026-10-15 08:05 UTC.