fallback: legalize: G_FLDEXP s16,s32

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_FLDEXP s16,s32
Occurrences:	28 in 18 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 04ca53e65f
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 (28):

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.1d0e0dee96.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-intrinsics.1e1d844d84.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi lp64d`
half-intrinsics.3a2326a884.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zdinx -mattr=+zhinx -verify-machineinstrs -target-abi ilp32`
half-intrinsics.3be2e87f42.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32d`
half-intrinsics.4840b18e85.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi lp64d`
half-intrinsics.4b4fb5d984.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zfh -verify-machineinstrs -target-abi ilp32f`
half-intrinsics.52a8691357.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -verify-machineinstrs`
half-intrinsics.5553cd648a.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zhinxmin -verify-machineinstrs -target-abi ilp32`
half-intrinsics.6fcf4f060c.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -verify-machineinstrs`
half-intrinsics.75f326fe22.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zhinx -verify-machineinstrs -target-abi lp64`
half-intrinsics.7fa5caa30e.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zhinxmin -verify-machineinstrs -target-abi lp64`
half-intrinsics.a11f1ead63.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+d -mattr=+zfh -verify-machineinstrs -target-abi ilp32d`
half-intrinsics.a6abb0b425.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zdinx -mattr=+zhinx -verify-machineinstrs -target-abi lp64`
half-intrinsics.c52a5977df.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zfh -verify-machineinstrs -target-abi lp64f`
half-intrinsics.c562257c85.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zdinx -mattr=+zhinxmin -verify-machineinstrs -target-abi lp64`
half-intrinsics.e516e02f39.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zdinx -mattr=+zhinxmin -verify-machineinstrs -target-abi ilp32`
half-intrinsics.e867fd7594.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-intrinsics.ec51046f06.ll (mutant of half-intrinsics.ll)	ldexp_half	`-mtriple=riscv32 -mattr=+zhinx -verify-machineinstrs -target-abi ilp32`

Generated 2026-10-15 08:05 UTC.