fallback: legalize: G_ATOMICRMW_XCHG s64,p0
| Run: | explore-04ca53e65f-20261014-114124 |
| Kind: | fallback |
| Category: | legalize: G_ATOMICRMW_XCHG s64,p0 |
| Occurrences: | 8 in 3 configs, 3 test files |
| Snippet from: | forced-atomics.ll @rmw64_xchg_seq_cst via llvm-extract |
| Config: | -mtriple=riscv64 -mattr=+forced-atomics |
| Local check: | reproduces at 04ca53e65f |
| Compiler Explorer: | not uploaded (over --godbolt-limit or disabled) |
Snippet:
; Function Attrs: nounwind
define i64 @rmw64_xchg_seq_cst(ptr %p) #0 {
%v = atomicrmw xchg ptr %p, i64 1 seq_cst, align 8
ret i64 %v
}
attributes #0 = { nounwind }
Reproduce:
llc -mtriple=riscv64 -mattr=+forced-atomics -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+forced-atomics -global-isel=0 snippet.ll -o -
Local llc output:
remark: <unknown>:0:0: unable to legalize instruction: %1:_(s64) = G_ATOMICRMW_XCHG %0:_(p0), %2:_ :: (load store seq_cst (s64) on %ir.p) (in function: rmw64_xchg_seq_cst)
warning: Instruction selection used fallback path for rmw64_xchg_seq_cst
Occurrences (8):
| Input | Function | Config |
|---|
| atomic-rmw.ll | atomicrmw_xchg_i64_monotonic | -mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs |
| atomic-rmw.ll | atomicrmw_xchg_i64_acquire | -mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs |
| atomic-rmw.ll | atomicrmw_xchg_i64_release | -mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs |
| atomic-rmw.ll | atomicrmw_xchg_i64_acq_rel | -mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs |
| atomic-rmw.ll | atomicrmw_xchg_i64_seq_cst | -mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs |
| atomic-signext.ll | atomicrmw_xchg_i64_monotonic | -mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs |
| forced-atomics.ll | rmw64_xchg_seq_cst | -mtriple=riscv64 -mattr=+forced-atomics |
| forced-atomics.ll | rmw64_xchg_seq_cst | -mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence |
Generated 2026-10-15 08:05 UTC.