fallback: legalize: G

fallback: legalize: G_FMA s16

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_FMA s16
Occurrences:	56 in 12 configs, 3 test files
Snippet from:	half-arith.ll @fmadd_h via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
Local check:	reproduces at bc8218b282
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define half @fmadd_h(half %a, half %b, half %c) #0 {
  %1 = call half @llvm.fma.f16(half %a, half %b, half %c)
  ret half %1
}

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

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

Reproduce:

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

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %3:_(s16) = G_FMA %0:_, %1:_, %2:_ (in function: fmadd_h)
warning: Instruction selection used fallback path for fmadd_h

Occurrences (56) (first 50):

Input	Function	Config
half-arith.ll	fmadd_h	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-arith.ll	fmsub_h	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-arith.ll	fnmadd_h	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-arith.ll	fnmadd_h_2	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-arith.ll	fnmsub_h	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-arith.ll	fnmsub_h_2	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-arith.ll	fmadd_h	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.ll	fmsub_h	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.ll	fnmadd_h	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.ll	fnmadd_h_2	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.ll	fnmsub_h	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.ll	fnmsub_h_2	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.ll	fmadd_h	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-arith.ll	fmsub_h	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-arith.ll	fnmadd_h	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-arith.ll	fnmadd_h_2	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-arith.ll	fnmsub_h	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-arith.ll	fnmsub_h_2	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-arith.ll	fmadd_h	`-mtriple=riscv64 -verify-machineinstrs`
half-arith.ll	fmsub_h	`-mtriple=riscv64 -verify-machineinstrs`
half-arith.ll	fnmadd_h	`-mtriple=riscv64 -verify-machineinstrs`
half-arith.ll	fnmadd_h_2	`-mtriple=riscv64 -verify-machineinstrs`
half-arith.ll	fnmsub_h	`-mtriple=riscv64 -verify-machineinstrs`
half-arith.ll	fnmsub_h_2	`-mtriple=riscv64 -verify-machineinstrs`
half-intrinsics.ll	fma_f16	`-mtriple=riscv32 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32d`
half-intrinsics.ll	fma_f16	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-intrinsics.ll	fma_f16	`-mtriple=riscv32 -verify-machineinstrs`
half-intrinsics.ll	fma_f16	`-mtriple=riscv64 -mattr=+d -mattr=+zfhmin -verify-machineinstrs -target-abi lp64d`
half-intrinsics.ll	fma_f16	`-mtriple=riscv64 -mattr=+zfhmin -verify-machineinstrs -target-abi lp64f`
half-intrinsics.ll	fma_f16	`-mtriple=riscv64 -verify-machineinstrs`
half-zfa.ll	fma_neg_addend	`-mtriple=riscv32 -target-abi ilp32f -mattr=+zfa,+zfhmin`
half-zfa.ll	fma_neg_multiplicand	`-mtriple=riscv32 -target-abi ilp32f -mattr=+zfa,+zfhmin`
half-zfa.ll	fma_neg_addend_multiplicand	`-mtriple=riscv32 -target-abi ilp32f -mattr=+zfa,+zfhmin`
half-zfa.ll	fma_neg_addend	`-mtriple=riscv64 -target-abi lp64f -mattr=+zfa,+zfhmin`
half-zfa.ll	fma_neg_multiplicand	`-mtriple=riscv64 -target-abi lp64f -mattr=+zfa,+zfhmin`
half-zfa.ll	fma_neg_addend_multiplicand	`-mtriple=riscv64 -target-abi lp64f -mattr=+zfa,+zfhmin`
half-arith.032b4b85ec.ll (mutant of half-arith.ll)	fmsub_h	`-mtriple=riscv64 -mattr=+zhinxmin -verify-machineinstrs -target-abi lp64`
half-arith.032b4b85ec.ll (mutant of half-arith.ll)	fnmadd_h_2	`-mtriple=riscv64 -mattr=+zhinxmin -verify-machineinstrs -target-abi lp64`
half-arith.109cc4b3b0.ll (mutant of half-arith.ll)	fmsub_h	`-mtriple=riscv32 -mattr=+zhinxmin -verify-machineinstrs -target-abi ilp32`
half-arith.109cc4b3b0.ll (mutant of half-arith.ll)	fnmadd_h_2	`-mtriple=riscv32 -mattr=+zhinxmin -verify-machineinstrs -target-abi ilp32`
half-arith.1a9bf55235.ll (mutant of half-arith.ll)	fmsub_h	`-mtriple=riscv32 -mattr=+zhinx -verify-machineinstrs -target-abi ilp32`
half-arith.1a9bf55235.ll (mutant of half-arith.ll)	fnmadd_h_2	`-mtriple=riscv32 -mattr=+zhinx -verify-machineinstrs -target-abi ilp32`
half-arith.21b5be46a4.ll (mutant of half-arith.ll)	fmsub_h	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.21b5be46a4.ll (mutant of half-arith.ll)	fnmadd_h_2	`-mtriple=riscv32 -verify-machineinstrs`
half-arith.610f216a63.ll (mutant of half-arith.ll)	fmsub_h	`-mtriple=riscv64 -verify-machineinstrs`
half-arith.610f216a63.ll (mutant of half-arith.ll)	fnmadd_h_2	`-mtriple=riscv64 -verify-machineinstrs`
half-arith.7f1560e862.ll (mutant of half-arith.ll)	fmsub_h	`-mtriple=riscv64 -mattr=+zhinx -verify-machineinstrs -target-abi lp64`
half-arith.7f1560e862.ll (mutant of half-arith.ll)	fnmadd_h_2	`-mtriple=riscv64 -mattr=+zhinx -verify-machineinstrs -target-abi lp64`
half-arith.95cfec4395.ll (mutant of half-arith.ll)	fmsub_h	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`
half-arith.95cfec4395.ll (mutant of half-arith.ll)	fnmadd_h_2	`-mtriple=riscv32 -mattr=+zfhmin -verify-machineinstrs -target-abi ilp32f`

Generated 2026-10-15 08:05 UTC.