fallback: legalize: G_LSHR <4 x s16>

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_LSHR <4 x s16>
Occurrences:	12 in 5 configs, 3 test files
Snippet from:	rvp-simd-64.ll @test_psrli_h 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 <4 x i16> @test_psrli_h(<4 x i16> %a) {
  %res = lshr <4 x i16> %a, splat (i16 2)
  ret <4 x i16> %res
}

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: %3:_(<4 x s16>) = G_LSHR %0:_, %1:_(<4 x s16>) (in function: test_psrli_h)
warning: Instruction selection used fallback path for test_psrli_h

Occurrences (12):

Input	Function	Config
rvp-simd-64.ll	test_psrli_h	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psrl_hs	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psrl_hs_mask	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_pudiv_mulhu_h	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
srem-vector-lkk.0b4822fc49.ll (mutant of srem-vector-lkk.ll)	fold_srem_vec_1	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
srem-vector-lkk.25b65d411e.ll (mutant of srem-vector-lkk.ll)	fold_srem_vec_1	`-mtriple=riscv32 -verify-machineinstrs`
srem-vector-lkk.aeabe7df2b.ll (mutant of srem-vector-lkk.ll)	fold_srem_vec_1	`-mtriple=riscv64 -verify-machineinstrs`
srem-vector-lkk.ece7d2dfb9.ll (mutant of srem-vector-lkk.ll)	fold_srem_vec_1	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.20b317ae69.ll (mutant of urem-vector-lkk.ll)	fold_urem_vec_1	`-mtriple=riscv32 -verify-machineinstrs`
urem-vector-lkk.38b0518b83.ll (mutant of urem-vector-lkk.ll)	fold_urem_vec_1	`-mtriple=riscv32 -mattr=+m -verify-machineinstrs`
urem-vector-lkk.4c170cb920.ll (mutant of urem-vector-lkk.ll)	fold_urem_vec_1	`-mtriple=riscv64 -verify-machineinstrs`
urem-vector-lkk.91cf3126c4.ll (mutant of urem-vector-lkk.ll)	fold_urem_vec_1	`-mtriple=riscv64 -mattr=+m -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.