fallback: legalize: G_UITOFP s16,s128

Run:explore-bc8218b282-20261015-075519
Kind:fallback
Category:legalize: G_UITOFP s16,s128
Occurrences:7 in 3 configs, 1 test files
Snippet from:rv64-half-convert.ll @uitofp_i128_to_f16 via llvm-extract
Config:-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f
Local check:reproduces at bc8218b282
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define half @uitofp_i128_to_f16(i128 %a) #0 {
  %1 = uitofp 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_UITOFP %0:_(s128) (in function: uitofp_i128_to_f16)
warning: Instruction selection used fallback path for uitofp_i128_to_f16

Occurrences (7):

InputFunctionConfig
rv64-half-convert.lluitofp_i128_to_f16-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f
rv64-half-convert.lluitofp_i128_to_f16-mtriple=riscv64 -verify-machineinstrs -target-abi lp64
rv64-half-convert.2b48692499.ll (mutant of rv64-half-convert.ll)uitofp_i128_to_f16-mtriple=riscv64 -mattr=+zhinx -verify-machineinstrs -target-abi lp64
rv64-half-convert.2c8d30d796.ll (mutant of rv64-half-convert.ll)uitofp_i128_to_f16-mtriple=riscv64 -verify-machineinstrs -target-abi lp64
rv64-half-convert.35faecf37e.ll (mutant of rv64-half-convert.ll)uitofp_i128_to_f16-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f
rv64-half-convert.78dff82c39.ll (mutant of rv64-half-convert.ll)uitofp_i128_to_f16-mtriple=riscv64 -verify-machineinstrs -target-abi lp64
rv64-half-convert.7cac727e06.ll (mutant of rv64-half-convert.ll)uitofp_i128_to_f16-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f

Generated 2026-10-15 08:05 UTC.