fallback: legalize: G_FLDEXP s16,s32

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_FLDEXP s16,s32
Occurrences:	20 in 10 configs, 1 test files
Snippet from:	half-intrinsics.ll @ldexp_half via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi ilp32d`
Local check:	reproduces at bc8218b282
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define half @ldexp_half(half %x, i32 signext %y) #0 {
  %z = call half @llvm.ldexp.f16.i32(half %x, i32 %y)
  ret half %z
}

; Function Attrs: nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none)
declare half @llvm.ldexp.f16.i32(half, i32) #1

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

Reproduce:

llc -mtriple=riscv32 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi ilp32d -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi ilp32d -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %2:_(s16) = G_FLDEXP %0:_, %1:_(s32) (in function: ldexp_half)
warning: Instruction selection used fallback path for ldexp_half

Occurrences (20):

Input	Function	Config
half-intrinsics.ll	ldexp_half	`-mtriple=riscv32 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi ilp32d`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv32 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32d`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv32 -mattr=+zfh -verify-machineinstrs -target-abi ilp32f`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv32 -verify-machineinstrs`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv64 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi lp64d`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv64 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi lp64d`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-intrinsics.ll	ldexp_half	`-mtriple=riscv64 -verify-machineinstrs`
half-intrinsics.38d287580c.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi lp64d`
half-intrinsics.41912cc75e.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -verify-machineinstrs`
half-intrinsics.49ba84a2e3.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-intrinsics.6249af6591.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zfh -verify-machineinstrs -target-abi ilp32f`
half-intrinsics.acd6183c98.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi ilp32d`
half-intrinsics.ad75257aa4.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
half-intrinsics.ae5b97cf4d.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-intrinsics.daf152428c.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -verify-machineinstrs`
half-intrinsics.dd3803e873.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi lp64d`
half-intrinsics.f5a18f56c4.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32d`

Generated 2026-10-15 08:05 UTC.