make simplifyCFG erase invokes to readonly/readnone functions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159385 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nuno Lopes 2012-06-28 22:32:27 +00:00
parent c363c74c45
commit 7f71f5f6b8
2 changed files with 47 additions and 7 deletions

View File

@ -89,7 +89,6 @@ static void ChangeToUnreachable(Instruction *I, bool UseLLVMTrap) {
/// ChangeToCall - Convert the specified invoke into a normal call.
static void ChangeToCall(InvokeInst *II) {
BasicBlock *BB = II->getParent();
SmallVector<Value*, 8> Args(II->op_begin(), II->op_end() - 3);
CallInst *NewCall = CallInst::Create(II->getCalledValue(), Args, "", II);
NewCall->takeName(II);
@ -100,10 +99,7 @@ static void ChangeToCall(InvokeInst *II) {
// Follow the call by a branch to the normal destination.
BranchInst::Create(II->getNormalDest(), II);
// Update PHI nodes in the unwind destination
II->getUnwindDest()->removePredecessor(BB);
BB->getInstList().erase(II);
II->eraseFromParent();
}
static bool MarkAliveBlocks(BasicBlock *BB,
@ -163,7 +159,12 @@ static bool MarkAliveBlocks(BasicBlock *BB,
ChangeToUnreachable(II, true);
Changed = true;
} else if (II->doesNotThrow()) {
ChangeToCall(II);
if (II->use_empty() && II->onlyReadsMemory()) {
// jump to the normal destination branch.
BranchInst::Create(II->getNormalDest(), II);
II->eraseFromParent();
} else
ChangeToCall(II);
Changed = true;
}
}

View File

@ -3,7 +3,7 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
declare i32 @__gxx_personality_v0(...)
declare void @__cxa_call_unexpected(i8*)
declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly
declare i32 @read_only() nounwind readonly
; CHECK: @f1
@ -43,3 +43,42 @@ lpad:
tail call void @__cxa_call_unexpected(i8* %1) noreturn nounwind
unreachable
}
; CHECK: @f3
define i32 @f3() nounwind uwtable ssp {
; CHECK-NEXT: entry
entry:
; CHECK-NEXT: ret i32 3
%call = invoke i32 @read_only()
to label %invoke.cont unwind label %lpad
invoke.cont:
ret i32 3
lpad:
%0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
filter [0 x i8*] zeroinitializer
%1 = extractvalue { i8*, i32 } %0, 0
tail call void @__cxa_call_unexpected(i8* %1) noreturn nounwind
unreachable
}
; CHECK: @f4
define i32 @f4() nounwind uwtable ssp {
; CHECK-NEXT: entry
entry:
; CHECK-NEXT: call i32 @read_only()
%call = invoke i32 @read_only()
to label %invoke.cont unwind label %lpad
invoke.cont:
; CHECK-NEXT: ret i32 %call
ret i32 %call
lpad:
%0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
filter [0 x i8*] zeroinitializer
%1 = extractvalue { i8*, i32 } %0, 0
tail call void @__cxa_call_unexpected(i8* %1) noreturn nounwind
unreachable
}