fallback: legalize: G_FPTOUI

fallback: legalize: G_FPTOUI_SAT s16,s32

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_FPTOUI_SAT s16,s32
Occurrences:	4 in 4 configs, 1 test files
Snippet from:	float-convert.ll @fcvt_wu_s_sat_i16 via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
Local check:	reproduces at bc8218b282
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define zeroext i16 @fcvt_wu_s_sat_i16(float %a) #0 {
start:
  %0 = tail call i16 @llvm.fptoui.sat.i16.f32(float %a)
  ret i16 %0
}

; Function Attrs: nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none)
declare i16 @llvm.fptoui.sat.i16.f32(float) #1

attributes #0 = { nounwind }
attributes #1 = { nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none) }

Reproduce:

llc -mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %1:_(s16) = G_FPTOUI_SAT %0:_(s32) (in function: fcvt_wu_s_sat_i16)
warning: Instruction selection used fallback path for fcvt_wu_s_sat_i16

Occurrences (4):

Input	Function	Config
float-convert.ll	fcvt_wu_s_sat_i16	`-mtriple=riscv32 -mattr=+f -verify-machineinstrs -target-abi=ilp32f`
float-convert.ll	fcvt_wu_s_sat_i16	`-mtriple=riscv32 -verify-machineinstrs`
float-convert.ll	fcvt_wu_s_sat_i16	`-mtriple=riscv64 -mattr=+f -verify-machineinstrs -target-abi=lp64f`
float-convert.ll	fcvt_wu_s_sat_i16	`-mtriple=riscv64 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.