fallback: legalize: G_INTRINSIC_W_SIDE

fallback: legalize: G_INTRINSIC_W_SIDE_EFFECTS

Run:	main-04ca53e65f-20261014-105623
Kind:	fallback
Category:	legalize: G_INTRINSIC_W_SIDE_EFFECTS
Occurrences:	25 in 6 configs, 4 test files
Snippet from:	riscv-zihintpause.ll @test_pause via llvm-extract
Config:	`-mtriple=riscv32 -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

define void @test_pause() {
  call void @llvm.riscv.pause()
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.riscv.pause() #0

attributes #0 = { nocallback nofree nosync nounwind willreturn }

Reproduce:

llc -mtriple=riscv32 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -verify-machineinstrs -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.pause) (in function: test_pause)
warning: Instruction selection used fallback path for test_pause

Occurrences (25):

Input	Function	Config
riscv-zihintpause.ll	test_pause	`-mtriple=riscv32 -verify-machineinstrs`
riscv-zihintpause.ll	test_pause	`-mtriple=riscv64 -mattr=+zihintpause -verify-machineinstrs`
riscv-zihintpause.ll	test_pause	`-mtriple=riscv64 -verify-machineinstrs`
rv64-stackmap-nops.ll	test_shadow_optimization	`-mtriple=riscv64`
rv64-stackmap-nops.ll	test_shadow_optimization	`-mtriple=riscv64 -mattr=+c`
rv64-stackmap.ll	needsStackRealignment	`-mtriple=riscv64`
xmips-exectl.ll	test_mips_pause	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
xmips-exectl.ll	test_mips_ehb	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
xmips-exectl.ll	test_mips_ihb	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
riscv-zihintpause.0ef67f9fbc.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv32 -verify-machineinstrs`
riscv-zihintpause.2fcf75bed1.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv64 -verify-machineinstrs`
riscv-zihintpause.46c4bdd337.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv32 -verify-machineinstrs`
riscv-zihintpause.509bb9901d.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv64 -mattr=+zihintpause -verify-machineinstrs`
riscv-zihintpause.c58b4fd54a.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv64 -verify-machineinstrs`
riscv-zihintpause.c7b5aad9eb.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv64 -mattr=+zihintpause -verify-machineinstrs`
rv64-stackmap-nops.08110ba19f.ll (mutant of rv64-stackmap-nops.ll)	test_shadow_optimization	`-mtriple=riscv64 -mattr=+c`
rv64-stackmap-nops.b384a79674.ll (mutant of rv64-stackmap-nops.ll)	test_shadow_optimization	`-mtriple=riscv64`
rv64-stackmap-nops.bfdddc5f08.ll (mutant of rv64-stackmap-nops.ll)	test_shadow_optimization	`-mtriple=riscv64`
rv64-stackmap-nops.dc4657f56a.ll (mutant of rv64-stackmap-nops.ll)	test_shadow_optimization	`-mtriple=riscv64 -mattr=+c`
xmips-exectl.39911f1c70.ll (mutant of xmips-exectl.ll)	test_mips_pause	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
xmips-exectl.39911f1c70.ll (mutant of xmips-exectl.ll)	test_mips_ehb	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
xmips-exectl.39911f1c70.ll (mutant of xmips-exectl.ll)	test_mips_ihb	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
xmips-exectl.eab59e8873.ll (mutant of xmips-exectl.ll)	test_mips_pause	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
xmips-exectl.eab59e8873.ll (mutant of xmips-exectl.ll)	test_mips_ihb	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`
xmips-exectl.fde56270b8.ll (mutant of xmips-exectl.ll)	test_mips_ehb	`-mtriple=riscv64 -mcpu=mips-p8700 -O3 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.