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

Run:	main-04ca53e65f-20261014-105623
Kind:	fallback
Category:	translate: call llvm.experimental.constrained.acos.f64
Occurrences:	12 in 6 configs, 1 test files
Snippet from:	double-intrinsics-strict.ll @acos_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 @acos_f64(double %a) #0 {
  %1 = call double @llvm.experimental.constrained.acos.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.acos.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.acos.f64: '  %1 = call double @llvm.experimental.constrained.acos.f64(double %a, metadata !"round.dynamic", metadata !"fpexcept.strict") #2' (in function: acos_f64)
warning: Instruction selection used fallback path for acos_f64

Occurrences (12):

Input	Function	Config
double-intrinsics-strict.ll	acos_f64	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d`
double-intrinsics-strict.ll	acos_f64	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32`
double-intrinsics-strict.ll	acos_f64	`-mtriple=riscv32 -verify-machineinstrs -disable-strictnode-mutation`
double-intrinsics-strict.ll	acos_f64	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64d`
double-intrinsics-strict.ll	acos_f64	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64`
double-intrinsics-strict.ll	acos_f64	`-mtriple=riscv64 -verify-machineinstrs -disable-strictnode-mutation`
double-intrinsics-strict.166d7b8148.ll (mutant of double-intrinsics-strict.ll)	acos_f64	`-mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32`
double-intrinsics-strict.64b5ae3ffe.ll (mutant of double-intrinsics-strict.ll)	acos_f64	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64`
double-intrinsics-strict.78b2628c84.ll (mutant of double-intrinsics-strict.ll)	acos_f64	`-mtriple=riscv64 -verify-machineinstrs -disable-strictnode-mutation`
double-intrinsics-strict.820a9f204d.ll (mutant of double-intrinsics-strict.ll)	acos_f64	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=ilp32d`
double-intrinsics-strict.b7ce58a989.ll (mutant of double-intrinsics-strict.ll)	acos_f64	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -disable-strictnode-mutation -target-abi=lp64d`
double-intrinsics-strict.d0b7027628.ll (mutant of double-intrinsics-strict.ll)	acos_f64	`-mtriple=riscv32 -verify-machineinstrs -disable-strictnode-mutation`

Generated 2026-10-15 08:05 UTC.