fallback: legalize: G_FLDEXP s128,s32

Run:	main-04ca53e65f-20261014-113325
Kind:	fallback
Category:	legalize: G_FLDEXP s128,s32
Occurrences:	2 in 1 configs, 1 test files
Snippet from:	fp128.ll @ldexp_f128 via llvm-extract
Config:	`-mtriple=riscv32 -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define fp128 @ldexp_f128(fp128 %x, i32 %y) #0 {
  %z = call fp128 @llvm.ldexp.f128.i32(fp128 %x, i32 %y)
  ret fp128 %z
}

; Function Attrs: nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none)
declare fp128 @llvm.ldexp.f128.i32(fp128, i32) #1

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

Reproduce:

llc -mtriple=riscv32 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %4:_(s128) = G_FLDEXP %0:_, %1:_(s32) (in function: ldexp_f128)
warning: Instruction selection used fallback path for ldexp_f128

Occurrences (2):

Input	Function	Config
fp128.ll	ldexp_f128	`-mtriple=riscv32 -verify-machineinstrs`
fp128.101598fbac.ll (mutant of fp128.ll)	ldexp_f128	`-mtriple=riscv32 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.