fallback: legalize: G_STORE <16 x s1>,p0

Run:explore-04ca53e65f-20261014-114124
Kind:fallback
Category:legalize: G_STORE <16 x s1>,p0 NEW
Occurrences:2 in 2 configs, 1 test files
Snippet from:fastcc-int.4adc6b8ed2.ll (mutant of fastcc-int.ll) @caller via llvm-extract
Config:-mtriple=riscv32 -verify-machineinstrs
Local check:reproduces at 04ca53e65f
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

@G = external global <16 x i1>

; Function Attrs: nounwind
declare fastcc i32 @callee(<16 x i32>) #0

; Function Attrs: nounwind
define i32 @caller(<16 x i32> %A) #0 {
  %A2 = alloca i8, align 1
  store i8 poison, ptr %A2, align 1
  %C1 = icmp sle <16 x i32> %A, splat (i32 2147483647)
  %B = or i8 0, -1
  %C = call fastcc i32 @callee(<16 x i32> %A)
  store <16 x i1> %C1, ptr @G, align 2
  store i8 %B, ptr %A2, align 1
  ret i32 %C
}

attributes #0 = { nounwind }

Reproduce:

llc -mtriple=riscv32 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: G_STORE %6:_(<16 x s1>), %36:_(p0) :: (store (<16 x s1>) into @G) (in function: caller)
warning: Instruction selection used fallback path for caller

Occurrences (2):

InputFunctionConfig
fastcc-int.4adc6b8ed2.ll (mutant of fastcc-int.ll)caller-mtriple=riscv32 -verify-machineinstrs
fastcc-int.dae610ccc7.ll (mutant of fastcc-int.ll)caller-mtriple=riscv64 -verify-machineinstrs

Generated 2026-10-15 08:05 UTC.