fallback: legalize: G_CTLZ_ZERO_POISON s64,s129

Run:explore-04ca53e65f-20261014-114124
Kind:fallback
Category:legalize: G_CTLZ_ZERO_POISON s64,s129
Occurrences:3 in 1 configs, 1 test files
Snippet from:idiv_large.ll @udiv_i129 via llvm-extract
Config:-mtriple=riscv64
Local check:reproduces at 04ca53e65f
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

; Function Attrs: nounwind
define i129 @udiv_i129(i129 %x, i129 %y) #0 {
  %res = udiv i129 %x, %y
  ret i129 %res
}

attributes #0 = { nounwind }

Reproduce:

llc -mtriple=riscv64 -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %1104:_(s64) = G_CTLZ_ZERO_POISON %6:_(s129) (in function: udiv_i129)
warning: Instruction selection used fallback path for udiv_i129

Occurrences (3):

InputFunctionConfig
idiv_large.lludiv_i129-mtriple=riscv64
idiv_large.531a437120.ll (mutant of idiv_large.ll)udiv_i129-mtriple=riscv64
idiv_large.e87dca6d97.ll (mutant of idiv_large.ll)udiv_i129-mtriple=riscv64

Generated 2026-10-15 08:05 UTC.