forked from OSchip/llvm-project
Resubmit "[CorrelatedValuePropagation] Fix prof branch_weights metadata handling for SwitchInst"
This reverts commit5b32f60ec3. The fix is in commit4f9e68148b. This patch fixes the CorrelatedValuePropagation pass to keep prof branch_weights metadata of SwitchInst consistent. It makes use of SwitchInstProfUpdateWrapper. New tests are added. Reviewed By: nikic Differential Revision: https://reviews.llvm.org/D62126 llvm-svn: 362583
This commit is contained in:
Yevgeny Rouban
parent
fa449a9bb2
commit
a3e16719c4
|
|
@ -308,11 +308,11 @@ static bool processCmp(CmpInst *Cmp, LazyValueInfo *LVI) {
|
|||
/// that cannot fire no matter what the incoming edge can safely be removed. If
|
||||
/// a case fires on every incoming edge then the entire switch can be removed
|
||||
/// and replaced with a branch to the case destination.
|
||||
static bool processSwitch(SwitchInst *SI, LazyValueInfo *LVI,
|
||||
static bool processSwitch(SwitchInst *I, LazyValueInfo *LVI,
|
||||
DominatorTree *DT) {
|
||||
DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Lazy);
|
||||
Value *Cond = SI->getCondition();
|
||||
BasicBlock *BB = SI->getParent();
|
||||
Value *Cond = I->getCondition();
|
||||
BasicBlock *BB = I->getParent();
|
||||
|
||||
// If the condition was defined in same block as the switch then LazyValueInfo
|
||||
// currently won't say anything useful about it, though in theory it could.
|
||||
|
|
@ -329,67 +329,72 @@ static bool processSwitch(SwitchInst *SI, LazyValueInfo *LVI,
|
|||
for (auto *Succ : successors(BB))
|
||||
SuccessorsCount[Succ]++;
|
||||
|
||||
for (auto CI = SI->case_begin(), CE = SI->case_end(); CI != CE;) {
|
||||
ConstantInt *Case = CI->getCaseValue();
|
||||
{ // Scope for SwitchInstProfUpdateWrapper. It must not live during
|
||||
// ConstantFoldTerminator() as the underlying SwitchInst can be changed.
|
||||
SwitchInstProfUpdateWrapper SI(*I);
|
||||
|
||||
// Check to see if the switch condition is equal to/not equal to the case
|
||||
// value on every incoming edge, equal/not equal being the same each time.
|
||||
LazyValueInfo::Tristate State = LazyValueInfo::Unknown;
|
||||
for (pred_iterator PI = PB; PI != PE; ++PI) {
|
||||
// Is the switch condition equal to the case value?
|
||||
LazyValueInfo::Tristate Value = LVI->getPredicateOnEdge(CmpInst::ICMP_EQ,
|
||||
Cond, Case, *PI,
|
||||
BB, SI);
|
||||
// Give up on this case if nothing is known.
|
||||
if (Value == LazyValueInfo::Unknown) {
|
||||
State = LazyValueInfo::Unknown;
|
||||
break;
|
||||
for (auto CI = SI->case_begin(), CE = SI->case_end(); CI != CE;) {
|
||||
ConstantInt *Case = CI->getCaseValue();
|
||||
|
||||
// Check to see if the switch condition is equal to/not equal to the case
|
||||
// value on every incoming edge, equal/not equal being the same each time.
|
||||
LazyValueInfo::Tristate State = LazyValueInfo::Unknown;
|
||||
for (pred_iterator PI = PB; PI != PE; ++PI) {
|
||||
// Is the switch condition equal to the case value?
|
||||
LazyValueInfo::Tristate Value = LVI->getPredicateOnEdge(CmpInst::ICMP_EQ,
|
||||
Cond, Case, *PI,
|
||||
BB, SI);
|
||||
// Give up on this case if nothing is known.
|
||||
if (Value == LazyValueInfo::Unknown) {
|
||||
State = LazyValueInfo::Unknown;
|
||||
break;
|
||||
}
|
||||
|
||||
// If this was the first edge to be visited, record that all other edges
|
||||
// need to give the same result.
|
||||
if (PI == PB) {
|
||||
State = Value;
|
||||
continue;
|
||||
}
|
||||
|
||||
// If this case is known to fire for some edges and known not to fire for
|
||||
// others then there is nothing we can do - give up.
|
||||
if (Value != State) {
|
||||
State = LazyValueInfo::Unknown;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
// If this was the first edge to be visited, record that all other edges
|
||||
// need to give the same result.
|
||||
if (PI == PB) {
|
||||
State = Value;
|
||||
if (State == LazyValueInfo::False) {
|
||||
// This case never fires - remove it.
|
||||
BasicBlock *Succ = CI->getCaseSuccessor();
|
||||
Succ->removePredecessor(BB);
|
||||
CI = SI.removeCase(CI);
|
||||
CE = SI->case_end();
|
||||
|
||||
// The condition can be modified by removePredecessor's PHI simplification
|
||||
// logic.
|
||||
Cond = SI->getCondition();
|
||||
|
||||
++NumDeadCases;
|
||||
Changed = true;
|
||||
if (--SuccessorsCount[Succ] == 0)
|
||||
DTU.applyUpdatesPermissive({{DominatorTree::Delete, BB, Succ}});
|
||||
continue;
|
||||
}
|
||||
|
||||
// If this case is known to fire for some edges and known not to fire for
|
||||
// others then there is nothing we can do - give up.
|
||||
if (Value != State) {
|
||||
State = LazyValueInfo::Unknown;
|
||||
if (State == LazyValueInfo::True) {
|
||||
// This case always fires. Arrange for the switch to be turned into an
|
||||
// unconditional branch by replacing the switch condition with the case
|
||||
// value.
|
||||
SI->setCondition(Case);
|
||||
NumDeadCases += SI->getNumCases();
|
||||
Changed = true;
|
||||
break;
|
||||
}
|
||||
|
||||
// Increment the case iterator since we didn't delete it.
|
||||
++CI;
|
||||
}
|
||||
|
||||
if (State == LazyValueInfo::False) {
|
||||
// This case never fires - remove it.
|
||||
BasicBlock *Succ = CI->getCaseSuccessor();
|
||||
Succ->removePredecessor(BB);
|
||||
CI = SI->removeCase(CI);
|
||||
CE = SI->case_end();
|
||||
|
||||
// The condition can be modified by removePredecessor's PHI simplification
|
||||
// logic.
|
||||
Cond = SI->getCondition();
|
||||
|
||||
++NumDeadCases;
|
||||
Changed = true;
|
||||
if (--SuccessorsCount[Succ] == 0)
|
||||
DTU.applyUpdatesPermissive({{DominatorTree::Delete, BB, Succ}});
|
||||
continue;
|
||||
}
|
||||
if (State == LazyValueInfo::True) {
|
||||
// This case always fires. Arrange for the switch to be turned into an
|
||||
// unconditional branch by replacing the switch condition with the case
|
||||
// value.
|
||||
SI->setCondition(Case);
|
||||
NumDeadCases += SI->getNumCases();
|
||||
Changed = true;
|
||||
break;
|
||||
}
|
||||
|
||||
// Increment the case iterator since we didn't delete it.
|
||||
++CI;
|
||||
}
|
||||
|
||||
if (Changed)
|
||||
|
|
|
|||
|
|
@ -0,0 +1,119 @@
|
|||
; RUN: opt < %s -correlated-propagation -S | FileCheck %s
|
||||
|
||||
; Removed several cases from switch.
|
||||
define i32 @switch1(i32 %s) {
|
||||
; CHECK-LABEL: @switch1(
|
||||
; CHECK-NEXT: entry:
|
||||
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[S:%.*]], 0
|
||||
; CHECK-NEXT: br i1 [[CMP]], label [[NEGATIVE:%.*]], label [[OUT:%.*]]
|
||||
;
|
||||
entry:
|
||||
%cmp = icmp slt i32 %s, 0
|
||||
br i1 %cmp, label %negative, label %out
|
||||
|
||||
negative:
|
||||
; CHECK: negative:
|
||||
; CHECK-NEXT: switch i32 [[S]], label [[OUT]] [
|
||||
; CHECK-NEXT: i32 -2, label [[NEXT:%.*]]
|
||||
; CHECK-NEXT: i32 -1, label [[NEXT]]
|
||||
switch i32 %s, label %out [
|
||||
i32 0, label %out
|
||||
i32 1, label %out
|
||||
i32 -1, label %next
|
||||
i32 -2, label %next
|
||||
i32 2, label %out
|
||||
i32 3, label %out
|
||||
; CHECK-NEXT: !prof ![[MD0:[0-9]+]]
|
||||
], !prof !{!"branch_weights", i32 99, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6}
|
||||
|
||||
out:
|
||||
%p = phi i32 [ 1, %entry ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ]
|
||||
ret i32 %p
|
||||
|
||||
next:
|
||||
%q = phi i32 [ 0, %negative ], [ 0, %negative ]
|
||||
ret i32 %q
|
||||
}
|
||||
|
||||
; Removed all cases from switch.
|
||||
define i32 @switch2(i32 %s) {
|
||||
; CHECK-LABEL: @switch2(
|
||||
; CHECK-NEXT: entry:
|
||||
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[S:%.*]], 0
|
||||
; CHECK-NEXT: br i1 [[CMP]], label [[POSITIVE:%.*]], label [[OUT:%.*]]
|
||||
;
|
||||
entry:
|
||||
%cmp = icmp sgt i32 %s, 0
|
||||
br i1 %cmp, label %positive, label %out
|
||||
|
||||
positive:
|
||||
switch i32 %s, label %out [
|
||||
i32 0, label %out
|
||||
i32 -1, label %next
|
||||
i32 -2, label %next
|
||||
], !prof !{!"branch_weights", i32 99, i32 1, i32 2, i32 3}
|
||||
|
||||
out:
|
||||
%p = phi i32 [ -1, %entry ], [ 1, %positive ], [ 1, %positive ]
|
||||
ret i32 %p
|
||||
|
||||
next:
|
||||
%q = phi i32 [ 0, %positive ], [ 0, %positive ]
|
||||
ret i32 %q
|
||||
}
|
||||
|
||||
; Change switch into conditional branch.
|
||||
define i32 @switch3(i32 %s) {
|
||||
; CHECK-LABEL: @switch3(
|
||||
;
|
||||
entry:
|
||||
%cmp = icmp sgt i32 %s, 0
|
||||
br i1 %cmp, label %positive, label %out
|
||||
|
||||
positive:
|
||||
; CHECK: positive:
|
||||
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 %s, 1
|
||||
; CHECK-NEXT: br i1 [[CMP]], label [[NEXT:%.*]], label [[OUT:%.*]], !prof ![[MD1:[0-9]+]]
|
||||
switch i32 %s, label %out [
|
||||
i32 1, label %next
|
||||
i32 -1, label %next
|
||||
i32 -2, label %next
|
||||
], !prof !{!"branch_weights", i32 99, i32 1, i32 2, i32 3}
|
||||
|
||||
out:
|
||||
%p = phi i32 [ -1, %entry ], [ 1, %positive ]
|
||||
ret i32 %p
|
||||
|
||||
next:
|
||||
%q = phi i32 [ 0, %positive ], [ 0, %positive ], [ 0, %positive ]
|
||||
ret i32 %q
|
||||
}
|
||||
|
||||
; Removed all cases from switch.
|
||||
define i32 @switch4(i32 %s) {
|
||||
; CHECK-LABEL: @switch4(
|
||||
; CHECK-NEXT: entry:
|
||||
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[S:%.*]], 0
|
||||
; CHECK-NEXT: br i1 [[CMP]], label [[NEGATIVE:%.*]], label [[OUT:%.*]]
|
||||
;
|
||||
entry:
|
||||
%cmp = icmp slt i32 %s, 0
|
||||
br i1 %cmp, label %negative, label %out
|
||||
|
||||
negative:
|
||||
; CHECK: negative:
|
||||
; CHECK-NEXT: br label %out
|
||||
switch i32 %s, label %out [
|
||||
i32 0, label %out
|
||||
i32 1, label %out
|
||||
i32 2, label %out
|
||||
i32 3, label %out
|
||||
], !prof !{!"branch_weights", i32 99, i32 1, i32 2, i32 3, i32 4}
|
||||
|
||||
out:
|
||||
%p = phi i32 [ 1, %entry ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ]
|
||||
ret i32 %p
|
||||
}
|
||||
|
||||
; CHECK: ![[MD0]] = !{!"branch_weights", i32 99, i32 4, i32 3}
|
||||
; CHECK: ![[MD1]] = !{!"branch_weights", i32 1, i32 99}
|
||||
Loading…
Reference in New Issue