mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-23 02:29:18 +00:00
Add a routine to swap branch instruction operands, and update any
profile metadata at the same time. Use it to preserve metadata attached to a branch when re-writing it in InstCombine. Add metadata to the canonicalize_branch InstCombine test, and check that it is tranformed correctly. Reviewed by Nick Lewycky! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142168 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
1416dc29d8
commit
602650c988
@ -2367,6 +2367,13 @@ public:
|
||||
*(&Op<-1>() - idx) = (Value*)NewSucc;
|
||||
}
|
||||
|
||||
/// \brief Swap the successors of this branch instruction.
|
||||
///
|
||||
/// Swaps the successors of the branch instruction. This also swaps any
|
||||
/// branch weight metadata associated with the instruction so that it
|
||||
/// continues to map correctly to each operand.
|
||||
void swapSuccessors();
|
||||
|
||||
// Methods for support type inquiry through isa, cast, and dyn_cast:
|
||||
static inline bool classof(const BranchInst *) { return true; }
|
||||
static inline bool classof(const Instruction *I) {
|
||||
|
@ -1190,8 +1190,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) {
|
||||
!isa<Constant>(X)) {
|
||||
// Swap Destinations and condition...
|
||||
BI.setCondition(X);
|
||||
BI.setSuccessor(0, FalseDest);
|
||||
BI.setSuccessor(1, TrueDest);
|
||||
BI.swapSuccessors();
|
||||
return &BI;
|
||||
}
|
||||
|
||||
@ -1206,8 +1205,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) {
|
||||
Cond->setPredicate(FCmpInst::getInversePredicate(FPred));
|
||||
|
||||
// Swap Destinations and condition.
|
||||
BI.setSuccessor(0, FalseDest);
|
||||
BI.setSuccessor(1, TrueDest);
|
||||
BI.swapSuccessors();
|
||||
Worklist.Add(Cond);
|
||||
return &BI;
|
||||
}
|
||||
@ -1223,8 +1221,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) {
|
||||
ICmpInst *Cond = cast<ICmpInst>(BI.getCondition());
|
||||
Cond->setPredicate(ICmpInst::getInversePredicate(IPred));
|
||||
// Swap Destinations and condition.
|
||||
BI.setSuccessor(0, FalseDest);
|
||||
BI.setSuccessor(1, TrueDest);
|
||||
BI.swapSuccessors();
|
||||
Worklist.Add(Cond);
|
||||
return &BI;
|
||||
}
|
||||
|
@ -785,6 +785,27 @@ BranchInst::BranchInst(const BranchInst &BI) :
|
||||
SubclassOptionalData = BI.SubclassOptionalData;
|
||||
}
|
||||
|
||||
void BranchInst::swapSuccessors() {
|
||||
assert(isConditional() &&
|
||||
"Cannot swap successors of an unconditional branch");
|
||||
Op<-1>().swap(Op<-2>());
|
||||
|
||||
// Update profile metadata if present and it matches our structural
|
||||
// expectations.
|
||||
MDNode *ProfileData = getMetadata(LLVMContext::MD_prof);
|
||||
if (!ProfileData || ProfileData->getNumOperands() != 3)
|
||||
return;
|
||||
|
||||
// The first operand is the name. Fetch them backwards and build a new one.
|
||||
Value *Ops[] = {
|
||||
ProfileData->getOperand(0),
|
||||
ProfileData->getOperand(2),
|
||||
ProfileData->getOperand(1)
|
||||
};
|
||||
setMetadata(LLVMContext::MD_prof,
|
||||
MDNode::get(ProfileData->getContext(), Ops));
|
||||
}
|
||||
|
||||
BasicBlock *BranchInst::getSuccessorV(unsigned idx) const {
|
||||
return getSuccessor(idx);
|
||||
}
|
||||
|
@ -1,8 +1,23 @@
|
||||
; RUN: opt < %s -instcombine -S | FileCheck %s
|
||||
|
||||
; Test an already canonical branch to make sure we don't flip those.
|
||||
define i32 @test0(i32 %X, i32 %Y) {
|
||||
%C = icmp eq i32 %X, %Y
|
||||
br i1 %C, label %T, label %F, !prof !0
|
||||
|
||||
; CHECK: @test0
|
||||
; CHECK: %C = icmp eq i32 %X, %Y
|
||||
; CHECK: br i1 %C, label %T, label %F
|
||||
|
||||
T:
|
||||
ret i32 12
|
||||
F:
|
||||
ret i32 123
|
||||
}
|
||||
|
||||
define i32 @test1(i32 %X, i32 %Y) {
|
||||
%C = icmp ne i32 %X, %Y
|
||||
br i1 %C, label %T, label %F
|
||||
br i1 %C, label %T, label %F, !prof !1
|
||||
|
||||
; CHECK: @test1
|
||||
; CHECK: %C = icmp eq i32 %X, %Y
|
||||
@ -16,7 +31,7 @@ F:
|
||||
|
||||
define i32 @test2(i32 %X, i32 %Y) {
|
||||
%C = icmp ule i32 %X, %Y
|
||||
br i1 %C, label %T, label %F
|
||||
br i1 %C, label %T, label %F, !prof !2
|
||||
|
||||
; CHECK: @test2
|
||||
; CHECK: %C = icmp ugt i32 %X, %Y
|
||||
@ -30,7 +45,7 @@ F:
|
||||
|
||||
define i32 @test3(i32 %X, i32 %Y) {
|
||||
%C = icmp uge i32 %X, %Y
|
||||
br i1 %C, label %T, label %F
|
||||
br i1 %C, label %T, label %F, !prof !3
|
||||
|
||||
; CHECK: @test3
|
||||
; CHECK: %C = icmp ult i32 %X, %Y
|
||||
@ -42,3 +57,13 @@ F:
|
||||
ret i32 123
|
||||
}
|
||||
|
||||
!0 = metadata !{metadata !"branch_weights", i32 1, i32 2}
|
||||
!1 = metadata !{metadata !"branch_weights", i32 3, i32 4}
|
||||
!2 = metadata !{metadata !"branch_weights", i32 5, i32 6}
|
||||
!3 = metadata !{metadata !"branch_weights", i32 7, i32 8}
|
||||
; Base case shouldn't change.
|
||||
; CHECK: !0 = {{.*}} i32 1, i32 2}
|
||||
; Ensure that the branch metadata is reversed to match the reversals above.
|
||||
; CHECK: !1 = {{.*}} i32 4, i32 3}
|
||||
; CHECK: !2 = {{.*}} i32 6, i32 5}
|
||||
; CHECK: !3 = {{.*}} i32 8, i32 7}
|
||||
|
Loading…
Reference in New Issue
Block a user