fallback: legalize: G

fallback: legalize: G_SUB <2 x s64>

Run:	explore-04ca53e65f-20261014-114124
Kind:	fallback
Category:	legalize: G_SUB <2 x s64> NEW
Occurrences:	44 in 35 configs, 14 test files
Snippet from:	align.3f25ab0d1f.ll (mutant of align.ll) @foo via llvm-extract + llvm-reduce
Config:	`-mtriple=riscv32 -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	https://godbolt.org/z/xh9xhdx5o (llc-assertions-trunk, checked 2026-10-14 11:49 UTC): G reproduces

Snippet:

define <2 x i64> @foo(<2 x i64> %L) {
entry:
  %B1 = sub <2 x i64> zeroinitializer, %L
  ret <2 x i64> %B1
}

Compiler Explorer panes:

Pane	Options	Exit	Insts	stderr
GlobalISel	`-mtriple=riscv32 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.*`	0	17	remark: <unknown>:0:0: unable to legalize instruction: %5:_(<2 x s64>) = G_SUB %3:_, %0:_ (in function: foo) warning: Instruction selection used fallback path for foo
SelectionDAG (control)	`-mtriple=riscv32 -verify-machineinstrs -global-isel=0`	0	17	-

Reproduce:

llc -mtriple=riscv32 -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

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

Occurrences (44):

Input	Function	Config
align.3f25ab0d1f.ll (mutant of align.ll)	foo	`-mtriple=riscv32 -verify-machineinstrs`
align.d6683a0d2b.ll (mutant of align.ll)	foo	`-mtriple=riscv32 -mattr=+c -verify-machineinstrs`
debug-line.33980b9e30.ll (mutant of debug-line.ll)	foo	`-mtriple=riscv64`
inline-asm-clobbers.1247980e45.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv32 -mattr=+f -target-abi=ilp32 -verify-machineinstrs`
inline-asm-clobbers.259a73fdc9.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv64 -mattr=+d -target-abi=lp64 -verify-machineinstrs`
inline-asm-clobbers.41481dbc8a.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv32 -mattr=+d -target-abi ilp32d -verify-machineinstrs`
inline-asm-clobbers.53713d2b09.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv32 -mattr=+d -target-abi=ilp32 -verify-machineinstrs`
inline-asm-clobbers.6445764963.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv32 -target-abi=ilp32 -verify-machineinstrs`
inline-asm-clobbers.ab9b4c4fff.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv64 -mattr=+f -target-abi lp64f -verify-machineinstrs`
inline-asm-clobbers.d5e4ca7a5b.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv64 -target-abi=lp64 -verify-machineinstrs`
inline-asm-clobbers.eaea40907f.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv64 -mattr=+d -target-abi lp64d -verify-machineinstrs`
inline-asm-clobbers.f76a6f587f.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv64 -mattr=+f -target-abi=lp64 -verify-machineinstrs`
inline-asm-clobbers.fd5c4f63a4.ll (mutant of inline-asm-clobbers.ll)	testcase	`-mtriple=riscv32 -mattr=+f -target-abi ilp32f -verify-machineinstrs`
inline-asm-i-constraint-i1.e73e1cd6c8.ll (mutant of inline-asm-i-constraint-i1.ll)	foo	`-mtriple=riscv64-unknown-linux-gnu`
inline-option-directive.03f03b1208.ll (mutant of inline-option-directive.ll)	test	`-mtriple=riscv64`
note-gnu-property-zicfiss.1a5095671d.ll (mutant of note-gnu-property-zicfiss.ll)	f	`--mtriple=riscv32`
note-gnu-property-zicfiss.c47801a2b5.ll (mutant of note-gnu-property-zicfiss.ll)	f	`--mtriple=riscv64`
option-arch-experimental.b83461585f.ll (mutant of option-arch-experimental.ll)	f	`-mtriple=riscv64`
riscv-zihintpause.5ea9d3bc67.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv64 -mattr=+zihintpause -verify-machineinstrs`
riscv-zihintpause.a76857ebad.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv64 -verify-machineinstrs`
riscv-zihintpause.e7790dd656.ll (mutant of riscv-zihintpause.ll)	test_pause	`-mtriple=riscv32 -verify-machineinstrs`
rv64-stackmap-nops.9db94b359d.ll (mutant of rv64-stackmap-nops.ll)	test_shadow_optimization	`-mtriple=riscv64 -mattr=+c`
rv64-stackmap-nops.e03e0ad519.ll (mutant of rv64-stackmap-nops.ll)	test_shadow_optimization	`-mtriple=riscv64`
saverestore-zilsd-fixed-location.43b8d6587a.ll (mutant of saverestore-zilsd-fixed-location.ll)	fixed_location_sr	`-mtriple=riscv32 -mattr=+save-restore -verify-machineinstrs`
saverestore-zilsd-fixed-location.a737ab2fda.ll (mutant of saverestore-zilsd-fixed-location.ll)	fixed_location_sr	`-mtriple=riscv32 -mattr=+save-restore,+zilsd -verify-machineinstrs`
sched-model-load-latency.0b254bc796.ll (mutant of sched-model-load-latency.ll)	large_int	`-mtriple=riscv64 -mcpu=rocket-rv64 -verify-machineinstrs`
sched-model-load-latency.721ed4ab34.ll (mutant of sched-model-load-latency.ll)	large_int	`-mtriple=riscv64 -mcpu=rocket-rv64 -riscv-sched-load-latency=2 -verify-machineinstrs`
srodata.ac3add8295.ll (mutant of srodata.ll)	foo	`-mtriple=riscv64 -mattr=+d`
srodata.ac3add8295.ll (mutant of srodata.ll)	foo	`-mtriple=riscv64 -mattr=+d`
srodata.ac3add8295.ll (mutant of srodata.ll)	foo	`-mtriple=riscv64 -mattr=+d`
srodata.fb0ae7b2be.ll (mutant of srodata.ll)	foo	`-mtriple=riscv32 -mattr=+d`
srodata.fb0ae7b2be.ll (mutant of srodata.ll)	foo	`-mtriple=riscv32 -mattr=+d`
srodata.fb0ae7b2be.ll (mutant of srodata.ll)	foo	`-mtriple=riscv32 -mattr=+d`
target-abi-valid.2948a55071.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv64 -mattr=+d -target-abi lp64`
target-abi-valid.3aae0f4ca8.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv64 -target-abi lp64`
target-abi-valid.66a22f3b64.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv64`
target-abi-valid.6a833778ae.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv32 -mattr=+d -target-abi ilp32`
target-abi-valid.7d7b67876a.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv32 -target-abi ilp32`
target-abi-valid.8d698ec6d2.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv64 -mattr=+f -target-abi lp64`
target-abi-valid.a9aa9cb804.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv32`
target-abi-valid.e03a387715.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv64 -target-abi lp64e`
target-abi-valid.e58554eb3e.ll (mutant of target-abi-valid.ll)	nothing	`-mtriple=riscv32 -mattr=+f -target-abi ilp32`
xray-attribute-instrumentation.6b303616b4.ll (mutant of xray-attribute-instrumentation.ll)	foo	`-mtriple=riscv32-unknown-linux-gnu -mattr=+d,+c`
xray-attribute-instrumentation.c3c99a1cc5.ll (mutant of xray-attribute-instrumentation.ll)	foo	`-mtriple=riscv64-unknown-linux-gnu -mattr=+d,+c`

Generated 2026-10-15 08:05 UTC.