[PATCH] StructurizeCFG: Fix inverting a branch on an argument
Matt Arsenault
Matthew.Arsenault at amd.com
Thu Nov 21 15:47:27 PST 2013
Add a test case that doesn't have an infinite loop
http://llvm-reviews.chandlerc.com/D2196
CHANGE SINCE LAST DIFF
http://llvm-reviews.chandlerc.com/D2196?vs=5598&id=5724#toc
Files:
lib/Transforms/Scalar/StructurizeCFG.cpp
test/Transforms/StructurizeCFG/branch-on-argument.ll
Index: lib/Transforms/Scalar/StructurizeCFG.cpp
===================================================================
--- lib/Transforms/Scalar/StructurizeCFG.cpp
+++ lib/Transforms/Scalar/StructurizeCFG.cpp
@@ -323,21 +323,32 @@
if (match(Condition, m_Not(m_Value(Condition))))
return Condition;
- // Third: Check all the users for an invert
- BasicBlock *Parent = cast<Instruction>(Condition)->getParent();
- for (Value::use_iterator I = Condition->use_begin(),
- E = Condition->use_end(); I != E; ++I) {
+ if (Instruction *Inst = dyn_cast<Instruction>(Condition)) {
+ // Third: Check all the users for an invert
+ BasicBlock *Parent = Inst->getParent();
+ for (Value::use_iterator I = Condition->use_begin(),
+ E = Condition->use_end(); I != E; ++I) {
+
+ Instruction *User = dyn_cast<Instruction>(*I);
+ if (!User || User->getParent() != Parent)
+ continue;
- Instruction *User = dyn_cast<Instruction>(*I);
- if (!User || User->getParent() != Parent)
- continue;
+ if (match(*I, m_Not(m_Specific(Condition))))
+ return *I;
+ }
+
+ // Last option: Create a new instruction
+ return BinaryOperator::CreateNot(Condition, "", Parent->getTerminator());
+ }
- if (match(*I, m_Not(m_Specific(Condition))))
- return *I;
+ if (Argument *Arg = dyn_cast<Argument>(Condition)) {
+ BasicBlock &EntryBlock = Arg->getParent()->getEntryBlock();
+ return BinaryOperator::CreateNot(Condition,
+ Arg->getName() + ".inv",
+ EntryBlock.getTerminator());
}
- // Last option: Create a new instruction
- return BinaryOperator::CreateNot(Condition, "", Parent->getTerminator());
+ llvm_unreachable("Unhandled condition to invert");
}
/// \brief Build the condition for one edge
Index: test/Transforms/StructurizeCFG/branch-on-argument.ll
===================================================================
--- /dev/null
+++ test/Transforms/StructurizeCFG/branch-on-argument.ll
@@ -0,0 +1,47 @@
+; RUN: opt -S -o - -structurizecfg < %s | FileCheck %s
+
+; CHECK-LABEL: @invert_branch_on_arg_inf_loop(
+; CHECK: entry:
+; CHECK: %arg.inv = xor i1 %arg, true
+; CHECK: phi i1 [ false, %Flow1 ], [ %arg.inv, %entry ]
+define void @invert_branch_on_arg_inf_loop(i32 addrspace(1)* %out, i1 %arg) {
+entry:
+ br i1 %arg, label %for.end, label %for.body
+
+for.body: ; preds = %entry, %for.body
+ store i32 999, i32 addrspace(1)* %out, align 4
+ br label %for.body
+
+for.end: ; preds = %Flow
+ ret void
+}
+
+
+; CHECK-LABEL: @invert_branch_on_arg_jump_into_loop(
+; CHECK: entry:
+; CHECK: %arg.inv = xor i1 %arg, true
+; CHECK: Flow:
+; CHECK: Flow1:
+define void @invert_branch_on_arg_jump_into_loop(i32 addrspace(1)* %out, i32 %n, i1 %arg) {
+entry:
+ br label %for.body
+
+for.body:
+ %i = phi i32 [0, %entry], [%i.inc, %end.loop]
+ %ptr = getelementptr i32 addrspace(1)* %out, i32 %i
+ store i32 %i, i32 addrspace(1)* %ptr, align 4
+ br i1 %arg, label %mid.loop, label %end.loop
+
+mid.loop:
+ store i32 333, i32 addrspace(1)* %out, align 4
+ br label %for.end
+
+end.loop:
+ %i.inc = add i32 %i, 1
+ %cmp = icmp ne i32 %i.inc, %n
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+ ret void
+}
+
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D2196.2.patch
Type: text/x-patch
Size: 3369 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20131121/930dc21a/attachment.bin>
More information about the llvm-commits
mailing list