fallback: legalize: G_SREM <4 x s32>

Run:explore-bc8218b282-20261015-075519
Kind:fallback
Category:legalize: G_SREM <4 x s32> NEW
Occurrences:17 in 16 configs, 2 test files
Snippet from:atomic-load-zext.1bef298bf7.ll (mutant of atomic-load-zext.ll) @atomic_load_i16_unordered via llvm-extract + llvm-reduce
Config:-mtriple=riscv64 -mattr=+a,+zalasr -verify-machineinstrs
Local check:reproduces at bc8218b282
Compiler Explorer:https://godbolt.org/z/qcToTGx5f (llc-assertions-trunk, checked 2026-10-15 08:05 UTC): G reproduces

Snippet:

define <4 x i32> @atomic_load_i16_unordered() {
  %B = srem <4 x i32> splat (i32 1), zeroinitializer
  ret <4 x i32> %B
}

Compiler Explorer panes:

PaneOptionsExitInstsstderr
GlobalISel-mtriple=riscv64 -mattr=+a,+zalasr -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.*01remark: <unknown>:0:0: unable to legalize instruction: %5:_(<4 x s32>) = G_SREM %1:_, %3:_ (in function: atomic_load_i16_unordered)
warning: Instruction selection used fallback path for atomic_load_i16_unordered
SelectionDAG (control)-mtriple=riscv64 -mattr=+a,+zalasr -verify-machineinstrs -global-isel=001-

Reproduce:

llc -mtriple=riscv64 -mattr=+a,+zalasr -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+a,+zalasr -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %5:_(<4 x s32>) = G_SREM %1:_, %3:_ (in function: atomic_load_i16_unordered)
warning: Instruction selection used fallback path for atomic_load_i16_unordered

Occurrences (17):

InputFunctionConfig
atomic-load-zext.1bef298bf7.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv64 -mattr=+a,+zalasr -verify-machineinstrs
atomic-load-zext.4daa5d28f7.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv64 -mattr=+a,+ztso,+no-trailing-seq-cst-fence -verify-machineinstrs
atomic-load-zext.5f245e7c81.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv32 -mattr=+a,+zalasr,+ztso -verify-machineinstrs
atomic-load-zext.67c9f19511.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv64 -mattr=+a,+zalasr,+ztso -verify-machineinstrs
atomic-load-zext.72e7f6d3de.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv32 -verify-machineinstrs
atomic-load-zext.7bb5e79dbf.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv64 -mattr=+a -verify-machineinstrs
atomic-load-zext.8020ce25b8.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv64 -verify-machineinstrs
atomic-load-zext.8021a6186b.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv32 -mattr=+a,+no-trailing-seq-cst-fence -verify-machineinstrs
atomic-load-zext.90d6a6ac38.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv32 -mattr=+a -verify-machineinstrs
atomic-load-zext.960dc6d26b.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv64 -mattr=+a,+no-trailing-seq-cst-fence -verify-machineinstrs
atomic-load-zext.abbc7b647e.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv64 -mattr=+a,+ztso -verify-machineinstrs
atomic-load-zext.bb84529a0e.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv32 -mattr=+a,+zalasr -verify-machineinstrs
atomic-load-zext.c314f7eb13.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv32 -mattr=+a,+ztso -verify-machineinstrs
atomic-load-zext.e96390fc7d.ll (mutant of atomic-load-zext.ll)atomic_load_i16_unordered-mtriple=riscv32 -mattr=+a,+ztso,+no-trailing-seq-cst-fence -verify-machineinstrs
xqcibm-cto-clo-brev.0412501126.ll (mutant of xqcibm-cto-clo-brev.ll)test_ctlz_i8-mtriple=riscv32 -verify-machineinstrs
xqcibm-cto-clo-brev.8a8efbb0ad.ll (mutant of xqcibm-cto-clo-brev.ll)test_ctlz_i8-mtriple=riscv32 -mattr=+zbb,xqcibm -verify-machineinstrs
xqcibm-cto-clo-brev.beeace0095.ll (mutant of xqcibm-cto-clo-brev.ll)test_ctlz_i8-mtriple=riscv32 -mattr=+zbb -verify-machineinstrs

Generated 2026-10-15 08:05 UTC.