fallback: legalize: G

fallback: legalize: G_FCMP s32,s128

Run:	main-04ca53e65f-20261014-113325
Kind:	fallback
Category:	legalize: G_FCMP s32,s128
Occurrences:	10 in 4 configs, 3 test files
Snippet from:	fp128.ll @test_load_and_cmp via llvm-extract
Config:	`-mtriple=riscv32 -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

@x = external local_unnamed_addr global fp128, align 16
@y = external local_unnamed_addr global fp128, align 16

; Function Attrs: nounwind
define i32 @test_load_and_cmp() #0 {
  %1 = load fp128, ptr @x, align 16
  %2 = load fp128, ptr @y, align 16
  %cmp = fcmp une fp128 %1, %2
  %3 = zext i1 %cmp to i32
  ret i32 %3
}

attributes #0 = { nounwind }

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: %6:_(s32) = G_FCMP floatpred(une), %0:_(s128), %2:_ (in function: test_load_and_cmp)
warning: Instruction selection used fallback path for test_load_and_cmp

Occurrences (10):

Input	Function	Config
fp128.ll	test_load_and_cmp	`-mtriple=riscv32 -verify-machineinstrs`
fp128.101598fbac.ll (mutant of fp128.ll)	test_load_and_cmp	`-mtriple=riscv32 -verify-machineinstrs`
fp128.b26b124633.ll (mutant of fp128.ll)	fmaximum	`-mtriple=riscv32 -verify-machineinstrs`
fp128.f4e1a8cc32.ll (mutant of fp128.ll)	fmaximum	`-mtriple=riscv32 -verify-machineinstrs`
llvm.frexp.196584e201.ll (mutant of llvm.frexp.ll)	test_frexp_f128_i32_only_use_exp	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -target-abi=ilp32d`
llvm.frexp.5285249d4b.ll (mutant of llvm.frexp.ll)	test_frexp_f128_i32_only_use_exp	`-mtriple=riscv32 -verify-machineinstrs`
llvm.frexp.8d23f333e8.ll (mutant of llvm.frexp.ll)	test_frexp_f128_i32_only_use_exp	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -target-abi=ilp32`
musttail-indirect-args.5c73b36cce.ll (mutant of musttail-indirect-args.ll)	caller_musttail_two_indirect_swapped	`-mtriple=riscv32`
musttail-indirect-args.5c73b36cce.ll (mutant of musttail-indirect-args.ll)	caller_musttail_three_indirect_rotated	`-mtriple=riscv32`
musttail-indirect-args.cfb898650c.ll (mutant of musttail-indirect-args.ll)	caller_musttail_computed_and_forwarded	`-mtriple=riscv32`

Generated 2026-10-15 08:05 UTC.