fallback: legalize: G_INTRINSIC_W_SIDE_EFFECTS <2 x s32>,p0,<2 x s1>,s64,s32

Run:explore-bc8218b282-20261015-075519
Kind:fallback
Category:legalize: G_INTRINSIC_W_SIDE_EFFECTS <2 x s32>,p0,<2 x s1>,s64,s32 NEW
Occurrences:2 in 2 configs, 2 test files
Snippet from:zero-call-used-regs-v.df625500be.ll (mutant of zero-call-used-regs-v.ll) @all_arg via llvm-extract
Config:-verify-machineinstrs -mtriple=riscv64 -mattr=+v
Local check:reproduces at bc8218b282
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

@G.2 = external global <4 x float>

define void @all_arg() #0 {
entry:
  %A = alloca <4 x float>, align 16
  store <4 x float> poison, ptr %A, align 16
  %LGV = load <4 x float>, ptr @G.2, align 16
  %S = shufflevector <4 x float> splat (float 4.200000e+01), <4 x float> %LGV, <4 x i32> poison
  store <4 x float> %S, ptr %A, align 16
  ret void
}

attributes #0 = { "zero-call-used-regs"="all-arg" }

Reproduce:

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

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: G_INTRINSIC_W_SIDE_EFFECTS intrinsic(@llvm.riscv.seg2.store.mask), %4:_(<2 x s32>), %7:_(<2 x s32>), %0:_(p0), %8:_(<2 x s1>), %10:_(s64) :: (store (s32) into %ir.A) (in function: all_arg)
warning: Instruction selection used fallback path for all_arg

Occurrences (2):

InputFunctionConfig
urem-seteq-illegal-types.66884fca6f.ll (mutant of urem-seteq-illegal-types.ll)test_urem_even-mtriple=riscv64 -mattr=+m,+v -riscv-v-vector-bits-min=128
zero-call-used-regs-v.df625500be.ll (mutant of zero-call-used-regs-v.ll)all_arg-verify-machineinstrs -mtriple=riscv64 -mattr=+v

Generated 2026-10-15 08:05 UTC.