Reland r229944: EH: Prune unreachable resume instructions during Dwarf EH preparation

Fix the double-deletion of AnalysisResolver when delegating through to
Dwarf EH preparation by creating one from scratch. Hopefully the new
pass manager simplifies this.

This reverts commit r229952.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231719 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 111 insertions, 4 deletions

diff --git a/test/CodeGen/X86/dwarf-eh-prepare.ll b/test/CodeGen/X86/dwarf-eh-prepare.ll
index a3a70da866c..25572d868da 100644
--- a/test/CodeGen/X86/dwarf-eh-prepare.ll
+++ b/test/CodeGen/X86/dwarf-eh-prepare.ll
@@ -7,12 +7,13 @@
 @int_typeinfo = global i8 0
 
 declare void @might_throw()
+declare void @cleanup()
 
-define i32 @simple_catch() {
+define i32 @simple_cleanup_catch() {
   invoke void @might_throw()
           to label %cont unwind label %lpad
 
-; CHECK: define i32 @simple_catch()
+; CHECK-LABEL: define i32 @simple_cleanup_catch()
 ; CHECK: invoke void @might_throw()
 
 cont:
@@ -22,15 +23,18 @@ cont:
 
 lpad:
   %ehvals = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+      cleanup
       catch i8* @int_typeinfo
   %ehptr = extractvalue { i8*, i32 } %ehvals, 0
   %ehsel = extractvalue { i8*, i32 } %ehvals, 1
+  call void @cleanup()
   %int_sel = call i32 @llvm.eh.typeid.for(i8* @int_typeinfo)
   %int_match = icmp eq i32 %ehsel, %int_sel
   br i1 %int_match, label %catch_int, label %eh.resume
 
 ; CHECK: lpad:
 ; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+; CHECK: call void @cleanup()
 ; CHECK: call i32 @llvm.eh.typeid.for
 ; CHECK: br i1
 
@@ -41,11 +45,114 @@ catch_int:
 ; CHECK: ret i32 1
 
 eh.resume:
-  resume { i8*, i32 } %ehvals
+  %tmp_ehvals = insertvalue { i8*, i32 } undef, i8* %ehptr, 0
+  %new_ehvals = insertvalue { i8*, i32 } %tmp_ehvals, i32 %ehsel, 1
+  resume { i8*, i32 } %new_ehvals
 
 ; CHECK: eh.resume:
-; CHECK: call void @_Unwind_Resume(i8* %{{.*}})
+; CHECK-NEXT: call void @_Unwind_Resume(i8* %ehptr)
 }
 
+
+define i32 @catch_no_resume() {
+  invoke void @might_throw()
+          to label %cont unwind label %lpad
+
+cont:
+  ret i32 0
+
+lpad:
+  %ehvals = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+      catch i8* @int_typeinfo
+  %ehptr = extractvalue { i8*, i32 } %ehvals, 0
+  %ehsel = extractvalue { i8*, i32 } %ehvals, 1
+  %int_sel = call i32 @llvm.eh.typeid.for(i8* @int_typeinfo)
+  %int_match = icmp eq i32 %ehsel, %int_sel
+  br i1 %int_match, label %catch_int, label %eh.resume
+
+catch_int:
+  ret i32 1
+
+eh.resume:
+  %tmp_ehvals = insertvalue { i8*, i32 } undef, i8* %ehptr, 0
+  %new_ehvals = insertvalue { i8*, i32 } %tmp_ehvals, i32 %ehsel, 1
+  resume { i8*, i32 } %new_ehvals
+}
+
+; Check that we can prune the unreachable resume instruction.
+
+; CHECK-LABEL: define i32 @catch_no_resume() {
+; CHECK: invoke void @might_throw()
+; CHECK: ret i32 0
+; CHECK: lpad:
+; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+; CHECK-NOT: br i1
+; CHECK: ret i32 1
+; CHECK-NOT: call void @_Unwind_Resume
+; CHECK: {{^[}]}}
+
+
+define i32 @catch_cleanup_merge() {
+  invoke void @might_throw()
+          to label %inner_invoke unwind label %outer_lpad
+inner_invoke:
+  invoke void @might_throw()
+          to label %cont unwind label %inner_lpad
+cont:
+  ret i32 0
+
+outer_lpad:
+  %ehvals1 = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+      catch i8* @int_typeinfo
+  br label %catch.dispatch
+
+inner_lpad:
+  %ehvals2 = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+      cleanup
+      catch i8* @int_typeinfo
+  call void @cleanup()
+  br label %catch.dispatch
+
+catch.dispatch:
+  %ehvals = phi { i8*, i32 } [ %ehvals1, %outer_lpad ], [ %ehvals2, %inner_lpad ]
+  %ehptr = extractvalue { i8*, i32 } %ehvals, 0
+  %ehsel = extractvalue { i8*, i32 } %ehvals, 1
+  %int_sel = call i32 @llvm.eh.typeid.for(i8* @int_typeinfo)
+  %int_match = icmp eq i32 %ehsel, %int_sel
+  br i1 %int_match, label %catch_int, label %eh.resume
+
+catch_int:
+  ret i32 1
+
+eh.resume:
+  %tmp_ehvals = insertvalue { i8*, i32 } undef, i8* %ehptr, 0
+  %new_ehvals = insertvalue { i8*, i32 } %tmp_ehvals, i32 %ehsel, 1
+  resume { i8*, i32 } %new_ehvals
+}
+
+; We can't prune this merge because one landingpad is a cleanup pad.
+
+; CHECK-LABEL: define i32 @catch_cleanup_merge()
+; CHECK: invoke void @might_throw()
+; CHECK: invoke void @might_throw()
+; CHECK: ret i32 0
+;
+; CHECK: outer_lpad:
+; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+; CHECK: br label %catch.dispatch
+;
+; CHECK: inner_lpad:
+; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+; CHECK: call void @cleanup()
+; CHECK: br label %catch.dispatch
+;
+; CHECK: catch.dispatch:
+; CHECK: call i32 @llvm.eh.typeid.for
+; CHECK: br i1
+; CHECK: catch_int:
+; CHECK: ret i32 1
+; CHECK: eh.resume:
+; CHECK-NEXT: call void @_Unwind_Resume(i8* %ehptr)
+
 declare i32 @__gxx_personality_v0(...)
 declare i32 @llvm.eh.typeid.for(i8*)