fallback: legalize: G

fallback: legalize: G_SHL <8 x s8>

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_SHL <8 x s8>
Occurrences:	11 in 9 configs, 3 test files
Snippet from:	rvp-simd-64.ll @test_pslli_b via llvm-extract
Config:	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

define <8 x i8> @test_pslli_b(<8 x i8> %a) {
  %res = shl <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_SHL %0:_, %1:_(<8 x s8>) (in function: test_pslli_b)
warning: Instruction selection used fallback path for test_pslli_b

Occurrences (11):

Input	Function	Config
rvp-simd-64.ll	test_pslli_b	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psll_bs	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psll_bs_mask	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
condops.2a17b98637.ll (mutant of condops.ll)	sub1	`-mtriple=riscv64 -target-abi=lp64f -mattr=+f,+zbs,+zicond`
condops.ac8ef0917a.ll (mutant of condops.ll)	sub1	`-mtriple=riscv32 -target-abi=ilp32f -mattr=+f,+zbs`
condops.ad3927464c.ll (mutant of condops.ll)	sub1	`-mtriple=riscv64 -target-abi=lp64f -mattr=+f,+zbs`
condops.ca5e45e048.ll (mutant of condops.ll)	sub1	`-mtriple=riscv64 -target-abi=lp64f -mattr=+f,+xtheadbs,+xtheadcondmov`
condops.decdb8ec74.ll (mutant of condops.ll)	sub1	`-mtriple=riscv32 -target-abi=ilp32f -mattr=+f,+zbs,+zicond`
sfb-merge-base-offset.324dbbcf51.ll (mutant of sfb-merge-base-offset.ll)	load_cond_ga_word_addr_cond	`-mtriple=riscv32 -verify-machineinstrs -mattr=+short-forward-branch-iload`
sfb-merge-base-offset.49ed03d568.ll (mutant of sfb-merge-base-offset.ll)	load_cond_ga_word_addr_cond	`-mtriple=riscv64 -verify-machineinstrs -mattr=+short-forward-branch-iload`
sfb-merge-base-offset.73601d179a.ll (mutant of sfb-merge-base-offset.ll)	load_cond_ga_word_addr_cond	`-mtriple=riscv32 -verify-machineinstrs -mattr=+xqci,+short-forward-branch-iload`

Generated 2026-10-15 08:05 UTC.