fallback: legalize: G

fallback: legalize: G_XOR <2 x s64>

Run:	main-bc8218b282-20261015-074651
Kind:	fallback
Category:	legalize: G_XOR <2 x s64> NEW
Occurrences:	12 in 12 configs, 2 test files
Snippet from:	load-store-pair.22ed8619e5.ll (mutant of load-store-pair.ll) @testi via llvm-extract + llvm-reduce
Config:	`-mtriple=riscv64 -target-abi=lp64d -mattr=+d,+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs`
Local check:	reproduces at bc8218b282
Compiler Explorer:	https://godbolt.org/z/rKhh6qKhh (llc-assertions-trunk, checked 2026-10-14 11:04 UTC): G reproduces

Snippet:

define <2 x i64> @testi(<2 x i64> %LGV1) {
entry:
  %B = xor <2 x i64> zeroinitializer, %LGV1
  ret <2 x i64> %B
}

Compiler Explorer panes:

Pane	Options	Exit	Insts	stderr
GlobalISel	`-mtriple=riscv64 -target-abi=lp64d -mattr=+d,+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.*`	0	1	remark: <unknown>:0:0: unable to legalize instruction: %5:_(<2 x s64>) = G_XOR %3:_, %0:_ (in function: testi) warning: Instruction selection used fallback path for testi
SelectionDAG (control)	`-mtriple=riscv64 -target-abi=lp64d -mattr=+d,+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs -global-isel=0`	0	1	-

Reproduce:

llc -mtriple=riscv64 -target-abi=lp64d -mattr=+d,+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -target-abi=lp64d -mattr=+d,+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %5:_(<2 x s64>) = G_XOR %3:_, %0:_ (in function: testi)
warning: Instruction selection used fallback path for testi

Occurrences (12):

Input	Function	Config
double-mem.23c5ce1137.ll (mutant of double-mem.ll)	fld_fsd_global	`-mtriple=riscv64 -mattr=+zdinx -verify-machineinstrs -target-abi=lp64`
double-mem.2d1c2590e1.ll (mutant of double-mem.ll)	fld_fsd_global	`-mtriple=riscv32 -mattr=+d -verify-machineinstrs -target-abi=ilp32d`
double-mem.d7834cb175.ll (mutant of double-mem.ll)	fld_fsd_global	`-mtriple=riscv64 -mattr=+d -verify-machineinstrs -target-abi=lp64d`
load-store-pair.22ed8619e5.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv64 -target-abi=lp64d -mattr=+d,+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs`
load-store-pair.4ce8ada632.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv32 -mattr=+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs`
load-store-pair.50149f390e.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv32 -target-abi=ilp32d -mattr=+d -verify-machineinstrs`
load-store-pair.6f3587e3ca.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv64 -verify-machineinstrs`
load-store-pair.8ea8786df6.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv32 -verify-machineinstrs`
load-store-pair.cce5b171ce.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv64 -mcpu=mips-p8700 -mattr=+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs`
load-store-pair.d47129bd5e.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv64 -mattr=+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs`
load-store-pair.dcb059aa2b.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv32 -target-abi=ilp32d -mattr=+d,+Xmipslsp -riscv-mips-load-store-pairs=1 -verify-machineinstrs`
load-store-pair.f4fa8ce28a.ll (mutant of load-store-pair.ll)	testi	`-mtriple=riscv64 -target-abi=lp64d -mattr=+d -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.