fallback: legalize: G

fallback: legalize: G_LSHR <8 x s8>

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_LSHR <8 x s8>
Occurrences:	20 in 17 configs, 5 test files
Snippet from:	rvp-simd-64.ll @test_psrli_b 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 <8 x i8> @test_psrli_b(<8 x i8> %a) {
  %res = lshr <8 x i8> %a, splat (i8 2)
  ret <8 x i8> %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:_(<8 x s8>) = G_LSHR %0:_, %1:_(<8 x s8>) (in function: test_psrli_b)
warning: Instruction selection used fallback path for test_psrli_b

Occurrences (20):

Input	Function	Config
rvp-simd-64.ll	test_psrli_b	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psrl_bs	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psrl_bs_mask	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_pudiv_mulhu_b	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
float-br-fcmp.01777a1c12.ll (mutant of float-br-fcmp.ll)	br_fcmp_oeq	`-mtriple=riscv64 -mattr=+f -verify-machineinstrs -target-abi=lp64f`
float-br-fcmp.c08b365ab5.ll (mutant of float-br-fcmp.ll)	br_fcmp_oeq	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
machine-sink-jumptable-edge-split.0954243c51.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv32 -code-model=small -mattr=+xqcili,+xqcisls,+zba -O3`
machine-sink-jumptable-edge-split.3a39660834.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv32 -code-model=small -mattr=+xqcili,+zba -O3`
machine-sink-jumptable-edge-split.49f768633c.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv32 -code-model=medium -mattr=+zba -O3`
machine-sink-jumptable-edge-split.58c32fe769.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv64 -relocation-model=pic -mattr=+zba -O3`
machine-sink-jumptable-edge-split.9a3949911d.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv64 -code-model=medium -mattr=+zba -O3`
machine-sink-jumptable-edge-split.b749754346.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv32 -relocation-model=pic -mattr=+zba -O3`
machine-sink-jumptable-edge-split.c04c46fc20.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv64 -code-model=small -mattr=+zba -O3`
machine-sink-jumptable-edge-split.f4e668bdda.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv32 -code-model=small -mattr=+zba -O3`
machine-sink-jumptable-edge-split.ff0143e30e.ll (mutant of machine-sink-jumptable-edge-split.ll)	sink_through_jt	`-mtriple=riscv64 -code-model=small -mattr=+experimental-zilx -O3`
prolog-epilogue.4252558026.ll (mutant of prolog-epilogue.ll)	frame_2048b	`-mtriple=riscv32 -verify-machineinstrs`
prolog-epilogue.b624eb6fc9.ll (mutant of prolog-epilogue.ll)	frame_2048b	`-mtriple=riscv64 -verify-machineinstrs -mattr=+zba`
prolog-epilogue.cf7eaaa28f.ll (mutant of prolog-epilogue.ll)	frame_2048b	`-mtriple=riscv64 -verify-machineinstrs`
prolog-epilogue.d2fdee144f.ll (mutant of prolog-epilogue.ll)	frame_2048b	`-mtriple=riscv32 -verify-machineinstrs -mattr=+zba`
xcvbi.cfec6d0267.ll (mutant of xcvbi.ll)	select_beqimm_1	`-O0 -mtriple=riscv32 -mattr=+xcvbi -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.