[llvm-commits] [llvm] r154642 - in /llvm/trunk: lib/Transforms/Scalar/ObjCARC.cpp test/Transforms/ObjCARC/basic.ll
Dan Gohman
gohman at apple.com
Thu Apr 12 17:59:57 PDT 2012
Author: djg
Date: Thu Apr 12 19:59:57 2012
New Revision: 154642
URL: http://llvm.org/viewvc/llvm-project?rev=154642&view=rev
Log:
Don't move objc_autorelease calls past autorelease pool boundaries when
optimizing autorelease calls on phi nodes with null operands.
This fixes rdar://11207070.
Modified:
llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
llvm/trunk/test/Transforms/ObjCARC/basic.ll
Modified: llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp?rev=154642&r1=154641&r2=154642&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp Thu Apr 12 19:59:57 2012
@@ -1963,6 +1963,7 @@
/// use here.
enum DependenceKind {
NeedsPositiveRetainCount,
+ AutoreleasePoolBoundary,
CanChangeRetainCount,
RetainAutoreleaseDep, ///< Blocks objc_retainAutorelease.
RetainAutoreleaseRVDep, ///< Blocks objc_retainAutoreleaseReturnValue.
@@ -1992,6 +1993,19 @@
}
}
+ case AutoreleasePoolBoundary: {
+ InstructionClass Class = GetInstructionClass(Inst);
+ switch (Class) {
+ case IC_AutoreleasepoolPop:
+ case IC_AutoreleasepoolPush:
+ // These mark the end and begin of an autorelease pool scope.
+ return true;
+ default:
+ // Nothing else does this.
+ return false;
+ }
+ }
+
case CanChangeRetainCount: {
InstructionClass Class = GetInstructionClass(Inst);
switch (Class) {
@@ -2009,6 +2023,7 @@
case RetainAutoreleaseDep:
switch (GetBasicInstructionClass(Inst)) {
case IC_AutoreleasepoolPop:
+ case IC_AutoreleasepoolPush:
// Don't merge an objc_autorelease with an objc_retain inside a different
// autoreleasepool scope.
return true;
@@ -2376,9 +2391,34 @@
// Check that there is nothing that cares about the reference
// count between the call and the phi.
- FindDependencies(NeedsPositiveRetainCount, Arg,
- Inst->getParent(), Inst,
- DependingInstructions, Visited, PA);
+ switch (Class) {
+ case IC_Retain:
+ case IC_RetainBlock:
+ // These can always be moved up.
+ break;
+ case IC_Release:
+ // These can't be moved across things that care about the retain count.
+ FindDependencies(NeedsPositiveRetainCount, Arg,
+ Inst->getParent(), Inst,
+ DependingInstructions, Visited, PA);
+ break;
+ case IC_Autorelease:
+ // These can't be moved across autorelease pool scope boundaries.
+ FindDependencies(AutoreleasePoolBoundary, Arg,
+ Inst->getParent(), Inst,
+ DependingInstructions, Visited, PA);
+ break;
+ case IC_RetainRV:
+ case IC_AutoreleaseRV:
+ // Don't move these; the RV optimization depends on the autoreleaseRV
+ // being tail called, and the retainRV being immediately after a call
+ // (which might still happen if we get lucky with codegen layout, but
+ // it's not worth taking the chance).
+ continue;
+ default:
+ llvm_unreachable("Invalid dependence flavor");
+ }
+
if (DependingInstructions.size() == 1 &&
*DependingInstructions.begin() == PN) {
Changed = true;
Modified: llvm/trunk/test/Transforms/ObjCARC/basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/basic.ll?rev=154642&r1=154641&r2=154642&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/basic.ll (original)
+++ llvm/trunk/test/Transforms/ObjCARC/basic.ll Thu Apr 12 19:59:57 2012
@@ -3,10 +3,12 @@
target datalayout = "e-p:64:64:64"
declare i8* @objc_retain(i8*)
+declare i8* @objc_retainAutoreleasedReturnValue(i8*)
declare void @objc_release(i8*)
declare i8* @objc_autorelease(i8*)
+declare i8* @objc_autoreleaseReturnValue(i8*)
declare void @objc_autoreleasePoolPop(i8*)
-declare void @objc_autoreleasePoolPush()
+declare i8* @objc_autoreleasePoolPush()
declare i8* @objc_retainBlock(i8*)
declare i8* @objc_retainedObject(i8*)
@@ -526,7 +528,7 @@
define void @test13d(i8* %x, i64 %n) {
entry:
call i8* @objc_retain(i8* %x) nounwind
- call void @objc_autoreleasePoolPush()
+ call i8* @objc_autoreleasePoolPush()
call i8* @objc_retain(i8* %x) nounwind
call void @use_pointer(i8* %x)
call void @use_pointer(i8* %x)
@@ -1400,7 +1402,7 @@
; CHECK-NEXT: call i8* @objc_autorelease(i8* %p)
; CHECK-NEXT: call void @use_pointer(i8* %p)
; CHECK-NEXT: call void @use_pointer(i8* %p)
-; CHECK-NEXT: call void @objc_autoreleasePoolPush()
+; CHECK-NEXT: call i8* @objc_autoreleasePoolPush()
; CHECK-NEXT: ret void
; CHECK-NEXT: }
define void @test43b(i8* %p) {
@@ -1410,7 +1412,7 @@
call i8* @objc_retain(i8* %p)
call void @use_pointer(i8* %p)
call void @use_pointer(i8* %p)
- call void @objc_autoreleasePoolPush()
+ call i8* @objc_autoreleasePoolPush()
call void @objc_release(i8* %p)
ret void
}
@@ -1797,6 +1799,78 @@
ret void
}
+; Move an autorelease past a phi with a null.
+
+; CHECK: define i8* @test65(
+; CHECK: if.then:
+; CHECK: call i8* @objc_autorelease(
+; CHECK: return:
+; CHECK-NOT: @objc_autorelease
+; CHECK: }
+define i8* @test65(i1 %x) {
+entry:
+ br i1 %x, label %return, label %if.then
+
+if.then: ; preds = %entry
+ %c = call i8* @returner()
+ %s = call i8* @objc_retainAutoreleasedReturnValue(i8* %c) nounwind
+ br label %return
+
+return: ; preds = %if.then, %entry
+ %retval = phi i8* [ %s, %if.then ], [ null, %entry ]
+ %q = call i8* @objc_autorelease(i8* %retval) nounwind
+ ret i8* %retval
+}
+
+; Don't move an autorelease past an autorelease pool boundary.
+
+; CHECK: define i8* @test65b(
+; CHECK: if.then:
+; CHECK-NOT: @objc_autorelease
+; CHECK: return:
+; CHECK: call i8* @objc_autorelease(
+; CHECK: }
+define i8* @test65b(i1 %x) {
+entry:
+ %t = call i8* @objc_autoreleasePoolPush()
+ br i1 %x, label %return, label %if.then
+
+if.then: ; preds = %entry
+ %c = call i8* @returner()
+ %s = call i8* @objc_retainAutoreleasedReturnValue(i8* %c) nounwind
+ br label %return
+
+return: ; preds = %if.then, %entry
+ %retval = phi i8* [ %s, %if.then ], [ null, %entry ]
+ call void @objc_autoreleasePoolPop(i8* %t)
+ %q = call i8* @objc_autorelease(i8* %retval) nounwind
+ ret i8* %retval
+}
+
+; Don't move an autoreleaseReuturnValue, which would break
+; the RV optimization.
+
+; CHECK: define i8* @test65c(
+; CHECK: if.then:
+; CHECK-NOT: @objc_autorelease
+; CHECK: return:
+; CHECK: call i8* @objc_autoreleaseReturnValue(
+; CHECK: }
+define i8* @test65c(i1 %x) {
+entry:
+ br i1 %x, label %return, label %if.then
+
+if.then: ; preds = %entry
+ %c = call i8* @returner()
+ %s = call i8* @objc_retainAutoreleasedReturnValue(i8* %c) nounwind
+ br label %return
+
+return: ; preds = %if.then, %entry
+ %retval = phi i8* [ %s, %if.then ], [ null, %entry ]
+ %q = call i8* @objc_autoreleaseReturnValue(i8* %retval) nounwind
+ ret i8* %retval
+}
+
declare void @bar(i32 ()*)
; A few real-world testcases.
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