fallback: legalize: G_SITOFP s16,s128

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_SITOFP s16,s128
Occurrences:	8 in 3 configs, 1 test files
Snippet from:	rv64-half-convert.ll @sitofp_i128_to_f16 via llvm-extract
Config:	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define half @sitofp_i128_to_f16(i128 %a) #0 {
  %1 = sitofp i128 %a to half
  ret half %1
}

attributes #0 = { nounwind }

Reproduce:

llc -mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %3:_(s16) = G_SITOFP %0:_(s128) (in function: sitofp_i128_to_f16)
warning: Instruction selection used fallback path for sitofp_i128_to_f16

Occurrences (8):

Input	Function	Config
rv64-half-convert.ll	sitofp_i128_to_f16	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
rv64-half-convert.ll	sitofp_i128_to_f16	`-mtriple=riscv64 -verify-machineinstrs -target-abi lp64`
rv64-half-convert.1e98b618e3.ll (mutant of rv64-half-convert.ll)	sitofp_i128_to_f16	`-mtriple=riscv64 -mattr=+zhinx -verify-machineinstrs -target-abi lp64`
rv64-half-convert.3af987a1b0.ll (mutant of rv64-half-convert.ll)	sitofp_i128_to_f16	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
rv64-half-convert.4edb045737.ll (mutant of rv64-half-convert.ll)	sitofp_i128_to_f16	`-mtriple=riscv64 -verify-machineinstrs -target-abi lp64`
rv64-half-convert.81f57a2c45.ll (mutant of rv64-half-convert.ll)	sitofp_i128_to_f16	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
rv64-half-convert.cc685a7849.ll (mutant of rv64-half-convert.ll)	sitofp_i128_to_f16	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
rv64-half-convert.e3ab59b525.ll (mutant of rv64-half-convert.ll)	sitofp_i128_to_f16	`-mtriple=riscv64 -verify-machineinstrs -target-abi lp64`

Generated 2026-10-15 08:05 UTC.