fallback: legalize: G

fallback: legalize: G_VAARG s32,p0

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_VAARG s32,p0
Occurrences:	36 in 6 configs, 1 test files
Snippet from:	vararg.ll @va1_va_arg via llvm-extract
Config:	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define i32 @va1_va_arg(ptr %fmt, ...) #0 {
  %va = alloca ptr, align 8
  call void @llvm.va_start.p0(ptr %va)
  %1 = va_arg ptr %va, i32
  call void @llvm.va_end.p0(ptr %va)
  ret i32 %1
}

; 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=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %18:_(s32) = G_VAARG %17:_(p0), 4 (in function: va1_va_arg)
warning: Instruction selection used fallback path for va1_va_arg

Occurrences (36):

Input	Function	Config
vararg.ll	va1_va_arg	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
vararg.ll	va1_va_arg_alloca	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
vararg.ll	va4_va_copy	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
vararg.ll	va6_no_fixed_args	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
vararg.ll	va1_va_arg	`-mtriple=riscv64 -mattr=+d -target-abi lp64f -verify-machineinstrs`
vararg.ll	va1_va_arg_alloca	`-mtriple=riscv64 -mattr=+d -target-abi lp64f -verify-machineinstrs`
vararg.ll	va4_va_copy	`-mtriple=riscv64 -mattr=+d -target-abi lp64f -verify-machineinstrs`
vararg.ll	va6_no_fixed_args	`-mtriple=riscv64 -mattr=+d -target-abi lp64f -verify-machineinstrs`
vararg.ll	va1_va_arg	`-mtriple=riscv64 -target-abi lp64e -frame-pointer=all -verify-machineinstrs`
vararg.ll	va1_va_arg_alloca	`-mtriple=riscv64 -target-abi lp64e -frame-pointer=all -verify-machineinstrs`
vararg.ll	va4_va_copy	`-mtriple=riscv64 -target-abi lp64e -frame-pointer=all -verify-machineinstrs`
vararg.ll	va6_no_fixed_args	`-mtriple=riscv64 -target-abi lp64e -frame-pointer=all -verify-machineinstrs`
vararg.ll	va1_va_arg	`-mtriple=riscv64 -target-abi lp64e -verify-machineinstrs`
vararg.ll	va1_va_arg_alloca	`-mtriple=riscv64 -target-abi lp64e -verify-machineinstrs`
vararg.ll	va4_va_copy	`-mtriple=riscv64 -target-abi lp64e -verify-machineinstrs`
vararg.ll	va6_no_fixed_args	`-mtriple=riscv64 -target-abi lp64e -verify-machineinstrs`
vararg.ll	va1_va_arg	`-mtriple=riscv64 -verify-machineinstrs`
vararg.ll	va1_va_arg_alloca	`-mtriple=riscv64 -verify-machineinstrs`
vararg.ll	va4_va_copy	`-mtriple=riscv64 -verify-machineinstrs`
vararg.ll	va6_no_fixed_args	`-mtriple=riscv64 -verify-machineinstrs`
vararg.ll	va1_va_arg	`-mtriple=riscv64 -verify-machineinstrs -frame-pointer=all`
vararg.ll	va1_va_arg_alloca	`-mtriple=riscv64 -verify-machineinstrs -frame-pointer=all`
vararg.ll	va4_va_copy	`-mtriple=riscv64 -verify-machineinstrs -frame-pointer=all`
vararg.ll	va6_no_fixed_args	`-mtriple=riscv64 -verify-machineinstrs -frame-pointer=all`
vararg.03f42faab9.ll (mutant of vararg.ll)	va6_no_fixed_args	`-mtriple=riscv64 -verify-machineinstrs -frame-pointer=all`
vararg.51ff03a652.ll (mutant of vararg.ll)	va6_no_fixed_args	`-mtriple=riscv64 -target-abi lp64e -verify-machineinstrs`
vararg.52d189578c.ll (mutant of vararg.ll)	va6_no_fixed_args	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
vararg.675a0165dc.ll (mutant of vararg.ll)	va6_no_fixed_args	`-mtriple=riscv64 -mattr=+d -target-abi lp64f -verify-machineinstrs`
vararg.7ee684e9f2.ll (mutant of vararg.ll)	va1_va_arg	`-mtriple=riscv64 -target-abi lp64e -verify-machineinstrs`
vararg.8790c92cf0.ll (mutant of vararg.ll)	va6_no_fixed_args	`-mtriple=riscv64 -verify-machineinstrs`
vararg.8ef72d1461.ll (mutant of vararg.ll)	va6_no_fixed_args	`-mtriple=riscv64 -target-abi lp64e -frame-pointer=all -verify-machineinstrs`
vararg.abf3dfb509.ll (mutant of vararg.ll)	va1_va_arg	`-mtriple=riscv64 -target-abi lp64e -frame-pointer=all -verify-machineinstrs`
vararg.bd16451c4e.ll (mutant of vararg.ll)	va1_va_arg	`-mtriple=riscv64 -verify-machineinstrs -frame-pointer=all`
vararg.e7007e08ea.ll (mutant of vararg.ll)	va1_va_arg	`-mtriple=riscv64 -mattr=+d -target-abi lp64f -verify-machineinstrs`
vararg.ed38332b79.ll (mutant of vararg.ll)	va1_va_arg	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
vararg.fae5ff3728.ll (mutant of vararg.ll)	va1_va_arg	`-mtriple=riscv64 -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.