[reg2mem]Skip non-sized Instructions

[Naville]

Summary

This should fix https://github.com/llvm/llvm-project/issues/58890

[nikic]

Can you please add a test case?

What about other unsized types? This is probably not a token specific problem.

[Naville]

In D137700#3916886, @nikic wrote:

Can you please add a test case?

What about other unsized types? This is probably not a token specific problem.

hey: I've attached a test case in the original github issue, not sure what else should be done here?

[nikic]

@Naville It looks like current test coverage is practically non-existent, but you can add your test case to llvm/test/Transforms/Reg2Mem.

[Naville]

Add test case

[Naville]

@nikic Added, anything more needed to do? I say we keep it restricted to token type for now and fix future issues if they appear

[Naville]

Add missing RUN line

[Naville]

Reformat to silent git-clang-format

[nikic]

llvm/lib/Transforms/Scalar/Reg2Mem.cpp

43

Check !Inst.getType()->isSized() instead. Also drop the {} for single-line if.

You can add this to your test case to test a non-token unsized value:

%opaque = type opaque

declare %opaque @ret_opaque()
declare void @pass_opaque(%opaque)

define void @test() {
  %x = call %opaque @ret_opaque()
  br label %next

next:
  call void @pass_opaque(%opaque %x)
  ret void
}

llvm/test/Transforms/Reg2Mem/catchswitch-crash.ll

2

Use RUN: opt -passes=reg2mem -S < %s | FileCheck %s and update_test_checks.py to generate check lines.

7

Drop all of these, they shouldn't be necessary.

11

Drop the dso_local and local_unnamed_addr, they shouldn't be necessary.

34

Drop the attributes and metadata, they shouldn't be necessary.

[Naville]

Update test case

[Naville]

@nikic Thanks for the suggestion, fixed and please check

[nikic]

llvm/test/Transforms/Reg2Mem/catchswitch-crash.ll

2

It looks like something went wrong here and no check lines were generated, which makes the test fail now. I wonder whether this might be related to the weird function names? Maybe replacing them with something like @test would make it work?

[Naville]

Fix broken test case due weird Windows mangling

[Naville]

@nikic Thanks, yeah the Windows name mangling was the issue, guess that's a bug for another day. Updated the test case which now has proper "CHECK*" tags

[nikic]

LGTM

If you don't have commit access, can you tell me which Name <email> to use for the commit?

[Naville]

This comment has been deleted.

[Naville]

Add TestCast

llvm/lib/Transforms/Scalar/Reg2Mem.cpp

 using namespace llvm;
 
 #define DEBUG_TYPE "reg2mem"
 
 STATISTIC(NumRegsDemoted, "Number of registers demoted");
 STATISTIC(NumPhisDemoted, "Number of phi-nodes demoted");
 
 static bool valueEscapes(const Instruction &Inst) {
+  if (!Inst.getType()->isSized())
+    return false;
+
   const BasicBlock *BB = Inst.getParent();
   for (const User *U : Inst.users()) {
     const Instruction *UI = cast<Instruction>(U);
     if (UI->getParent() != BB || isa<PHINode>(UI))
       return true;
   }
   return false;
 }

llvm/test/Transforms/Reg2Mem/catchswitch-crash.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=reg2mem -S < %s | FileCheck %s
+
+declare void @"read_mem"()
+
+define void @"memcpy_seh"() personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*) {
+; CHECK-LABEL: @memcpy_seh(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %"reg2mem alloca point" = bitcast i32 0 to i32
+; CHECK-NEXT:    invoke void @read_mem()
+; CHECK-NEXT:    to label [[CLEANUP:%.*]] unwind label [[CATCH_DISPATCH:%.*]]
+; CHECK:       catch.dispatch:
+; CHECK-NEXT:    [[TMP0:%.*]] = catchswitch within none [label %__except] unwind to caller
+; CHECK:       __except:
+; CHECK-NEXT:    [[TMP1:%.*]] = catchpad within [[TMP0]] [i8* null]
+; CHECK-NEXT:    unreachable
+; CHECK:       cleanup:
+; CHECK-NEXT:    ret void
+;
+entry:
+  invoke void @"read_mem"()
+  to label %cleanup unwind label %catch.dispatch
+
+catch.dispatch:                                   ; preds = %entry
+  %0 = catchswitch within none [label %__except] unwind to caller
+
+__except:                                         ; preds = %catch.dispatch
+  %1 = catchpad within %0 [i8* null]
+  unreachable
+
+cleanup:                                          ; preds = %entry
+  ret void
+}
+
+declare i32 @__C_specific_handler(...)

llvm/test/Transforms/Reg2Mem/non-token-test.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=reg2mem -S < %s | FileCheck %s
+
+%opaque = type opaque
+
+declare %opaque @ret_opaque()
+declare void @pass_opaque(%opaque)
+
+define void @test() {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:    %"reg2mem alloca point" = bitcast i32 0 to i32
+; CHECK-NEXT:    [[X:%.*]] = call [[OPAQUE:%.*]] @ret_opaque()
+; CHECK-NEXT:    br label [[NEXT:%.*]]
+; CHECK:       next:
+; CHECK-NEXT:    call void @pass_opaque([[OPAQUE]] [[X]])
+; CHECK-NEXT:    ret void
+;
+  %x = call %opaque @ret_opaque()
+  br label %next
+
+next:
+  call void @pass_opaque(%opaque %x)
+  ret void
+}