fallback: legalize: G_INVOKE_REGION_START

Snippet:

declare void @throw_exception()

declare i32 @__gxx_personality_v0(...)

declare ptr @__cxa_begin_catch(ptr)

declare void @__cxa_end_catch()

define void @test1() personality ptr @__gxx_personality_v0 {
entry:
  invoke void @throw_exception()
          to label %try.cont unwind label %lpad

lpad:                                             ; preds = %entry
  %0 = landingpad { ptr, i32 }
          catch ptr null
  %1 = extractvalue { ptr, i32 } %0, 0
  %2 = tail call ptr @__cxa_begin_catch(ptr %1)
  tail call void @__cxa_end_catch()
  br label %try.cont

try.cont:                                         ; preds = %lpad, %entry
  ret void
}

Reproduce:

llc -mtriple=riscv32 --code-model=medium -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv32 --code-model=medium -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: G_INVOKE_REGION_START (in function: test1)
warning: Instruction selection used fallback path for test1

Occurrences (52) (first 50):

Generated 2026-10-15 08:05 UTC.