fallback: translate: call llvm.is.fpclass.nxv2f64

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	translate: call llvm.is.fpclass.nxv2f64
Occurrences:	1 in 1 configs, 1 test files
Snippet from:	combine-is_fpclass.ll @splat_constant_f64_isinf_false via llvm-extract
Config:	`-mtriple=riscv64 -mattr=+v,+f,+d`
Local check:	reproduces at bc8218b282
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

define <vscale x 2 x i1> @splat_constant_f64_isinf_false() {
  %res = call <vscale x 2 x i1> @llvm.is.fpclass.nxv2f64(<vscale x 2 x double> splat (double 1.000000e+00), /* (inf) */ i32 516)
  ret <vscale x 2 x i1> %res
}

; Function Attrs: nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none)
declare <vscale x 2 x i1> @llvm.is.fpclass.nxv2f64(<vscale x 2 x double>, i32 immarg) #0

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

Reproduce:

llc -mtriple=riscv64 -mattr=+v,+f,+d -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+v,+f,+d -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to translate instruction: call llvm.is.fpclass.nxv2f64: '  %res = call <vscale x 2 x i1> @llvm.is.fpclass.nxv2f64(<vscale x 2 x double> splat (double 1.000000e+00), /* (inf) */ i32 516)' (in function: splat_constant_f64_isinf_false)
warning: Instruction selection used fallback path for splat_constant_f64_isinf_false

Occurrences (1):

Input	Function	Config
combine-is_fpclass.ll	splat_constant_f64_isinf_false	`-mtriple=riscv64 -mattr=+v,+f,+d`

Generated 2026-10-15 08:05 UTC.