fallback: legalize: G_MERGE_VALUES s128,s64

Run:main-04ca53e65f-20261014-105623
Kind:fallback
Category:legalize: G_MERGE_VALUES s128,s64 NEW
Occurrences:1 in 1 configs, 1 test files
Snippet from:idiv_large.23a978e2ee.ll (mutant of idiv_large.ll) @udiv_i65 via llvm-extract
Config:-mtriple=riscv64
Local check:reproduces at 04ca53e65f
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

@G = external global i65

; Function Attrs: nounwind
define i65 @udiv_i65(i65 %x, i65 %y) #0 {
  %res = udiv i65 %x, %y
  store i65 %res, ptr @G, align 4
  ret i65 %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: %29:_(s128) = G_MERGE_VALUES %34:_(s64), %35:_(s64) (in function: udiv_i65)
warning: Instruction selection used fallback path for udiv_i65

Occurrences (1):

InputFunctionConfig
idiv_large.23a978e2ee.ll (mutant of idiv_large.ll)udiv_i65-mtriple=riscv64

Generated 2026-10-15 08:05 UTC.