fallback: translate: call llvm.experimental.constrained.atan.f64

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	translate: call llvm.experimental.constrained.atan.f64
Occurrences:	12 in 6 configs, 1 test files
Snippet from:	double-intrinsics-strict.ll @atan_f64 via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind strictfp
define double @atan_f64(double %a) #0 {
  %1 = call double @llvm.experimental.constrained.atan.f64(double %a, metadata !"round.dynamic", metadata !"fpexcept.strict") #2
  ret double %1
}

; Function Attrs: nocallback nofree nosync nounwind strictfp willreturn memory(inaccessiblemem: readwrite)
declare double @llvm.experimental.constrained.atan.f64(double, metadata, metadata) #1

attributes #0 = { nounwind strictfp }
attributes #1 = { nocallback nofree nosync nounwind strictfp willreturn memory(inaccessiblemem: readwrite) }
attributes #2 = { strictfp }

Reproduce:

llc -mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to translate instruction: call llvm.experimental.constrained.atan.f64: '  %1 = call double @llvm.experimental.constrained.atan.f64(double %a, metadata !"round.dynamic", metadata !"fpexcept.strict") #2' (in function: atan_f64)
warning: Instruction selection used fallback path for atan_f64

Occurrences (12):

Input	Function	Config
double-intrinsics-strict.ll	atan_f64	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d`
double-intrinsics-strict.ll	atan_f64	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32`
double-intrinsics-strict.ll	atan_f64	`-mtriple=riscv32 -verify-machineinstrs -disable-strictnode-mutation`
double-intrinsics-strict.ll	atan_f64	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64d`
double-intrinsics-strict.ll	atan_f64	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64`
double-intrinsics-strict.ll	atan_f64	`-mtriple=riscv64 -verify-machineinstrs -disable-strictnode-mutation`
double-intrinsics-strict.54d78c343f.ll (mutant of double-intrinsics-strict.ll)	atan_f64	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32`
double-intrinsics-strict.78949837fa.ll (mutant of double-intrinsics-strict.ll)	atan_f64	`-mtriple=riscv64 -verify-machineinstrs -disable-strictnode-mutation`
double-intrinsics-strict.9e59e5cb06.ll (mutant of double-intrinsics-strict.ll)	atan_f64	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d`
double-intrinsics-strict.a53dc144a2.ll (mutant of double-intrinsics-strict.ll)	atan_f64	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64`
double-intrinsics-strict.af5b40976b.ll (mutant of double-intrinsics-strict.ll)	atan_f64	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64d`
double-intrinsics-strict.c82a50e202.ll (mutant of double-intrinsics-strict.ll)	atan_f64	`-mtriple=riscv32 -verify-machineinstrs -disable-strictnode-mutation`

Generated 2026-10-15 08:05 UTC.