fallback: legalize: G

fallback: legalize: G_VAARG s64,p0

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_VAARG s64,p0
Occurrences:	21 in 7 configs, 1 test files
Snippet from:	vararg.ll @va2_va_arg via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+d -target-abi ilp32d -verify-machineinstrs`
Local check:	reproduces at bc8218b282
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define i64 @va2_va_arg(ptr %fmt, ...) #0 {
  %va = alloca ptr, align 8
  call void @llvm.va_start.p0(ptr %va)
  %1 = va_arg ptr %va, double
  call void @llvm.va_end.p0(ptr %va)
  %2 = bitcast double %1 to i64
  ret i64 %2
}

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.va_end.p0(ptr) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.va_start.p0(ptr) #1

attributes #0 = { nounwind }
attributes #1 = { nocallback nofree nosync nounwind willreturn }

Reproduce:

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

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %18:_(s64) = G_VAARG %17:_(p0), 8 (in function: va2_va_arg)
warning: Instruction selection used fallback path for va2_va_arg

Occurrences (21):

Input	Function	Config
vararg.ll	va2_va_arg	`-mtriple=riscv32 -mattr=+d -target-abi ilp32d -verify-machineinstrs`
vararg.ll	va3_va_arg	`-mtriple=riscv32 -mattr=+d -target-abi ilp32d -verify-machineinstrs`
vararg.ll	va2_va_arg	`-mtriple=riscv32 -mattr=+d -target-abi ilp32f -verify-machineinstrs`
vararg.ll	va3_va_arg	`-mtriple=riscv32 -mattr=+d -target-abi ilp32f -verify-machineinstrs`
vararg.ll	va2_va_arg	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs`
vararg.ll	va3_va_arg	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs`
vararg.ll	va2_va_arg	`-mtriple=riscv32 -target-abi ilp32e -frame-pointer=all -verify-machineinstrs`
vararg.ll	va3_va_arg	`-mtriple=riscv32 -target-abi ilp32e -frame-pointer=all -verify-machineinstrs`
vararg.ll	va2_va_arg	`-mtriple=riscv32 -target-abi ilp32e -verify-machineinstrs`
vararg.ll	va3_va_arg	`-mtriple=riscv32 -target-abi ilp32e -verify-machineinstrs`
vararg.ll	va2_va_arg	`-mtriple=riscv32 -verify-machineinstrs`
vararg.ll	va3_va_arg	`-mtriple=riscv32 -verify-machineinstrs`
vararg.ll	va2_va_arg	`-mtriple=riscv32 -verify-machineinstrs -frame-pointer=all`
vararg.ll	va3_va_arg	`-mtriple=riscv32 -verify-machineinstrs -frame-pointer=all`
vararg.0b0450ee5f.ll (mutant of vararg.ll)	va2_va_arg	`-mtriple=riscv32 -mattr=+d -target-abi ilp32d -verify-machineinstrs`
vararg.1d42e20a7f.ll (mutant of vararg.ll)	va2_va_arg	`-mtriple=riscv32 -target-abi ilp32e -verify-machineinstrs`
vararg.230f8a3b89.ll (mutant of vararg.ll)	va2_va_arg	`-mtriple=riscv32 -mattr=+d -target-abi ilp32f -verify-machineinstrs`
vararg.4bbe300593.ll (mutant of vararg.ll)	va2_va_arg	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs`
vararg.6f04a04fd4.ll (mutant of vararg.ll)	va2_va_arg	`-mtriple=riscv32 -target-abi ilp32e -frame-pointer=all -verify-machineinstrs`
vararg.77c1ee32b2.ll (mutant of vararg.ll)	va2_va_arg	`-mtriple=riscv32 -verify-machineinstrs`
vararg.ce59a7a46a.ll (mutant of vararg.ll)	va2_va_arg	`-mtriple=riscv32 -verify-machineinstrs -frame-pointer=all`

Generated 2026-10-15 08:05 UTC.