Inlining often produces landingpad instructions with repeated

catch or repeated filter clauses.  Teach instcombine a bunch
of tricks for simplifying landingpad clauses.  Currently the
code only recognizes the GNU C++ and Ada personality functions,
but that doesn't stop it doing a bunch of "generic" transforms
which are hopefully fine for any real-world personality function.
If these "generic" transforms turn out not to be generic, they
can always be conditioned on the personality function.  Probably
someone should add the ObjC++ personality function.  I didn't as
I don't know anything about it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140852 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 157 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/LandingPadClauses.ll b/test/Transforms/InstCombine/LandingPadClauses.ll
new file mode 100644
index 0000000000..e96bf4c7f4
--- /dev/null
+++ b/test/Transforms/InstCombine/LandingPadClauses.ll
@@ -0,0 +1,157 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+@T1 = external constant i32
+@T2 = external constant i32
+@T3 = external constant i32
+
+declare i32 @generic_personality(i32, i64, i8*, i8*)
+declare i32 @__gxx_personality_v0(i32, i64, i8*, i8*)
+
+declare void @bar()
+
+define void @foo_generic() {
+; CHECK: @foo_generic
+  invoke void @bar()
+    to label %cont.a unwind label %lpad.a
+cont.a:
+  invoke void @bar()
+    to label %cont.b unwind label %lpad.b
+cont.b:
+  invoke void @bar()
+    to label %cont.c unwind label %lpad.c
+cont.c:
+  invoke void @bar()
+    to label %cont.d unwind label %lpad.d
+cont.d:
+  invoke void @bar()
+    to label %cont.e unwind label %lpad.e
+cont.e:
+  invoke void @bar()
+    to label %cont.f unwind label %lpad.f
+cont.f:
+  invoke void @bar()
+    to label %cont.g unwind label %lpad.g
+cont.g:
+  invoke void @bar()
+    to label %cont.h unwind label %lpad.h
+cont.h:
+  ret void
+
+lpad.a:
+  %a = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          catch i32* @T1
+          catch i32* @T2
+          catch i32* @T1
+          catch i32* @T2
+  unreachable
+; CHECK: %a = landingpad
+; CHECK-NEXT: @T1
+; CHECK-NEXT: @T2
+; CHECK-NEXT: unreachable
+
+lpad.b:
+  %b = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          filter [0 x i32*] zeroinitializer
+          catch i32* @T1
+  unreachable
+; CHECK: %b = landingpad
+; CHECK-NEXT: filter
+; CHECK-NEXT: unreachable
+
+lpad.c:
+  %c = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          catch i32* @T1
+          filter [1 x i32*] [i32* @T1]
+          catch i32* @T2
+  unreachable
+; CHECK: %c = landingpad
+; CHECK-NEXT: @T1
+; CHECK-NEXT: filter [0 x i32*]
+; CHECK-NEXT: unreachable
+
+lpad.d:
+  %d = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          filter [3 x i32*] zeroinitializer
+  unreachable
+; CHECK: %d = landingpad
+; CHECK-NEXT: filter [1 x i32*] zeroinitializer
+; CHECK-NEXT: unreachable
+
+lpad.e:
+  %e = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          catch i32* @T1
+          filter [3 x i32*] [i32* @T1, i32* @T2, i32* @T2]
+  unreachable
+; CHECK: %e = landingpad
+; CHECK-NEXT: @T1
+; CHECK-NEXT: filter [1 x i32*] [i32* @T2]
+; CHECK-NEXT: unreachable
+
+lpad.f:
+  %f = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          filter [2 x i32*] [i32* @T2, i32* @T1]
+          filter [1 x i32*] [i32* @T1]
+  unreachable
+; CHECK: %f = landingpad
+; CHECK-NEXT: filter [1 x i32*] [i32* @T1]
+; CHECK-NEXT: unreachable
+
+lpad.g:
+  %g = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          filter [1 x i32*] [i32* @T1]
+          catch i32* @T3
+          filter [2 x i32*] [i32* @T2, i32* @T1]
+  unreachable
+; CHECK: %g = landingpad
+; CHECK-NEXT: filter [1 x i32*] [i32* @T1]
+; CHECK-NEXT: catch i32* @T3
+; CHECK-NEXT: unreachable
+
+lpad.h:
+  %h = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @generic_personality
+          filter [2 x i32*] [i32* @T1, i32* null]
+          filter [1 x i32*] zeroinitializer
+  unreachable
+; CHECK: %h = landingpad
+; CHECK-NEXT: filter [1 x i32*] zeroinitializer
+; CHECK-NEXT: unreachable
+}
+
+define void @foo_cxx() {
+; CHECK: @foo_cxx
+  invoke void @bar()
+    to label %cont.a unwind label %lpad.a
+cont.a:
+  invoke void @bar()
+    to label %cont.b unwind label %lpad.b
+cont.b:
+  invoke void @bar()
+    to label %cont.c unwind label %lpad.c
+cont.c:
+  ret void
+
+lpad.a:
+  %a = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @__gxx_personality_v0
+          catch i32* null
+          catch i32* @T1
+  unreachable
+; CHECK: %a = landingpad
+; CHECK-NEXT: null
+; CHECK-NEXT: unreachable
+
+lpad.b:
+  %b = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @__gxx_personality_v0
+          filter [1 x i32*] zeroinitializer
+  unreachable
+; CHECK: %b = landingpad
+; CHECK-NEXT: cleanup
+; CHECK-NEXT: unreachable
+
+lpad.c:
+  %c = landingpad { i8*, i32 } personality i32 (i32, i64, i8*, i8*)* @__gxx_personality_v0
+          filter [2 x i32*] [i32* @T1, i32* null]
+  unreachable
+; CHECK: %c = landingpad
+; CHECK-NEXT: cleanup
+; CHECK-NEXT: unreachable
+}