fallback: legalize: G_LSHR <2 x s32>

Run:	main-04ca53e65f-20261014-105623
Kind:	fallback
Category:	legalize: G_LSHR <2 x s32>
Occurrences:	7 in 3 configs, 4 test files
Snippet from:	rvp-simd-64.ll @test_psrli_w 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 <2 x i32> @test_psrli_w(<2 x i32> %a) {
  %res = lshr <2 x i32> %a, splat (i32 2)
  ret <2 x i32> %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:_(<2 x s32>) = G_LSHR %0:_, %1:_(<2 x s32>) (in function: test_psrli_w)
warning: Instruction selection used fallback path for test_psrli_w

Occurrences (7):

Input	Function	Config
rvp-simd-64.ll	test_psrli_w	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psrl_ws	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psrl_ws_mask	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_psrl_ws_vec_shamt	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-32.cddd1509ff.ll (mutant of rvp-simd-32.ll)	test_pmulhr_h	`-mtriple=riscv32 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-widening-add-acc.98065af97c.ll (mutant of rvp-widening-add-acc.ll)	test_pwaddau_v2i16	`-mtriple=riscv64 -mattr=+experimental-p -verify-machineinstrs`
rvp-widening-sub-acc.e34b158430.ll (mutant of rvp-widening-sub-acc.ll)	test_pwsubau_v2i16	`-mtriple=riscv64 -mattr=+experimental-p -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.