fallback: legalize: G_ATOMIC

fallback: legalize: G_ATOMIC_CMPXCHG s32,p0

Run:	explore-bc8218b282-20261015-075519
Kind:	fallback
Category:	legalize: G_ATOMIC_CMPXCHG s32,p0
Occurrences:	42 in 6 configs, 2 test files
Snippet from:	forced-atomics.ll @rmw32_fadd_seq_cst via llvm-extract
Config:	`-mtriple=riscv32 -mattr=+forced-atomics`
Local check:	reproduces at bc8218b282
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define float @rmw32_fadd_seq_cst(ptr %p) #0 {
  %v = atomicrmw fadd ptr %p, float 1.000000e+00 seq_cst, align 4
  ret float %v
}

attributes #0 = { nounwind }

Reproduce:

llc -mtriple=riscv32 -mattr=+forced-atomics -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 -mattr=+forced-atomics -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %14:_(s32) = G_ATOMIC_CMPXCHG %0:_(p0), %2:_, %4:_ :: (load store seq_cst seq_cst (s32) on %ir.p) (in function: rmw32_fadd_seq_cst)
warning: Instruction selection used fallback path for rmw32_fadd_seq_cst

Occurrences (42):

Input	Function	Config
atomic-signext.ll	cmpxchg_i32_monotonic_monotonic_val0	`-mtriple=riscv32 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.ll	cmpxchg_i32_monotonic_monotonic_val1	`-mtriple=riscv32 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.ll	cmpxchg_i32_monotonic_crossbb	`-mtriple=riscv32 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.ll	cmpxchg_i32_monotonic_monotonic_val0	`-mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.ll	cmpxchg_i32_monotonic_monotonic_val1	`-mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.ll	cmpxchg_i32_monotonic_crossbb	`-mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs`
forced-atomics.ll	rmw32_fadd_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fsub_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fmin_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fmax_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.ll	cmpxchg32_monotonic	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.ll	cmpxchg32_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fadd_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	rmw32_fsub_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	rmw32_fmin_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	rmw32_fmax_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	cmpxchg32_monotonic	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	cmpxchg32_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	rmw32_fadd_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fsub_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fmin_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fmax_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.ll	cmpxchg32_monotonic	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.ll	cmpxchg32_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.ll	rmw32_fadd_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	rmw32_fsub_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	rmw32_fmin_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	rmw32_fmax_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	cmpxchg32_monotonic	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ll	cmpxchg32_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
atomic-signext.6bc9ecbdea.ll (mutant of atomic-signext.ll)	cmpxchg_i32_monotonic_monotonic_val1	`-mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.89c092aeaf.ll (mutant of atomic-signext.ll)	cmpxchg_i32_monotonic_monotonic_val1	`-mtriple=riscv32 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.c4039f24a2.ll (mutant of atomic-signext.ll)	cmpxchg_i32_monotonic_crossbb	`-mtriple=riscv32 -mattr=+zalrsc -verify-machineinstrs`
atomic-signext.cf765847e3.ll (mutant of atomic-signext.ll)	cmpxchg_i32_monotonic_crossbb	`-mtriple=riscv64 -mattr=+zalrsc -verify-machineinstrs`
forced-atomics.0e899462ff.ll (mutant of forced-atomics.ll)	rmw32_fmin_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.0e899462ff.ll (mutant of forced-atomics.ll)	cmpxchg32_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.22ebd339df.ll (mutant of forced-atomics.ll)	rmw32_fmin_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.22ebd339df.ll (mutant of forced-atomics.ll)	cmpxchg32_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.60ceb9fe48.ll (mutant of forced-atomics.ll)	rmw32_fmin_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.60ceb9fe48.ll (mutant of forced-atomics.ll)	cmpxchg32_seq_cst	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.7d3fa68fa7.ll (mutant of forced-atomics.ll)	rmw32_fmin_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.7d3fa68fa7.ll (mutant of forced-atomics.ll)	cmpxchg32_seq_cst	`-mtriple=riscv32 -mattr=+forced-atomics`

Generated 2026-10-15 08:05 UTC.