diff options
| -rw-r--r-- | lib/CodeGen/CGStmt.cpp | 10 | ||||
| -rw-r--r-- | test/CodeGen/switch-dce.c | 16 |
2 files changed, 25 insertions, 1 deletions
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp index b8b2cd9f3e..8bb45343db 100644 --- a/lib/CodeGen/CGStmt.cpp +++ b/lib/CodeGen/CGStmt.cpp @@ -873,7 +873,8 @@ void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) { return; } - // If the body of the case is just a 'break', try to not emit an empty block. + // If the body of the case is just a 'break', and if there was no fallthrough, + // try to not emit an empty block. if (isa<BreakStmt>(S.getSubStmt())) { JumpDest Block = BreakContinueStack.back().BreakBlock; @@ -882,6 +883,13 @@ void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) { llvm::APSInt CaseVal = S.getLHS()->EvaluateAsInt(getContext()); SwitchInsn->addCase(llvm::ConstantInt::get(getLLVMContext(), CaseVal), Block.getBlock()); + + // If there was a fallthrough into this case, make sure to redirect it to + // the end of the switch as well. + if (Builder.GetInsertBlock()) { + Builder.CreateBr(Block.getBlock()); + Builder.ClearInsertionPoint(); + } return; } } diff --git a/test/CodeGen/switch-dce.c b/test/CodeGen/switch-dce.c index 4013809cbf..bbb5f7e5aa 100644 --- a/test/CodeGen/switch-dce.c +++ b/test/CodeGen/switch-dce.c @@ -229,3 +229,19 @@ void test13(int x) { default: test13(42); break; } } + + +// Verify that case 42 only calls test14 once. +// CHECK: @test14 +// CHECK: call void @test14(i32 97) +// CHECK-NEXT: br label [[EPILOG2:%[0-9.a-z]+]] +// CHECK: call void @test14(i32 42) +// CHECK-NEXT: br label [[EPILOG2]] +void test14(int x) { + switch (x) { + case 42: test14(97); // fallthrough + case 11: break; + default: test14(42); break; + } +} + |