[llvm] r358419 - [LoopPred] Hoist and of predicated checks where legal
Philip Reames via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 15 08:53:25 PDT 2019
Author: reames
Date: Mon Apr 15 08:53:25 2019
New Revision: 358419
URL: http://llvm.org/viewvc/llvm-project?rev=358419&view=rev
Log:
[LoopPred] Hoist and of predicated checks where legal
If we have multiple range checks which can be predicated, hoist the and of the results outside the loop. This minorly cleans up the resulting IR, but the main motivation is as a building block for D60093.
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopPredication.cpp
llvm/trunk/test/Transforms/LoopPredication/basic.ll
llvm/trunk/test/Transforms/LoopPredication/widened.ll
Modified: llvm/trunk/lib/Transforms/Scalar/LoopPredication.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopPredication.cpp?rev=358419&r1=358418&r2=358419&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopPredication.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopPredication.cpp Mon Apr 15 08:53:25 2019
@@ -264,6 +264,12 @@ class LoopPredication {
Optional<LoopICmp> parseLoopLatchICmp();
+ /// Return an insertion point suitable for inserting a safe to speculate
+ /// instruction whose only user will be 'User' which has operands 'Ops'. A
+ /// trivial result would be the at the User itself, but we try to return a
+ /// loop invariant location if possible.
+ Instruction *findInsertPt(Instruction *User, ArrayRef<Value*> Ops);
+
bool CanExpand(const SCEV* S);
Value *expandCheck(SCEVExpander &Expander, IRBuilder<> &Builder,
ICmpInst::Predicate Pred, const SCEV *LHS,
@@ -438,6 +444,14 @@ bool LoopPredication::isSupportedStep(co
return Step->isOne() || (Step->isAllOnesValue() && EnableCountDownLoop);
}
+Instruction *LoopPredication::findInsertPt(Instruction *Use,
+ ArrayRef<Value*> Ops) {
+ for (Value *Op : Ops)
+ if (!L->isLoopInvariant(Op))
+ return Use;
+ return Preheader->getTerminator();
+}
+
bool LoopPredication::CanExpand(const SCEV* S) {
return SE->isLoopInvariant(S, L) && isSafeToExpand(S, *SE);
}
@@ -652,7 +666,7 @@ bool LoopPredication::widenGuardConditio
TotalWidened += NumWidened;
// Emit the new guard condition
- Builder.SetInsertPoint(Guard);
+ Builder.SetInsertPoint(findInsertPt(Guard, Checks));
Value *LastCheck = nullptr;
for (auto *Check : Checks)
if (!LastCheck)
@@ -684,7 +698,7 @@ bool LoopPredication::widenWidenableBran
TotalWidened += NumWidened;
// Emit the new guard condition
- Builder.SetInsertPoint(BI);
+ Builder.SetInsertPoint(findInsertPt(BI, Checks));
Value *LastCheck = nullptr;
for (auto *Check : Checks)
if (!LastCheck)
Modified: llvm/trunk/test/Transforms/LoopPredication/basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopPredication/basic.ll?rev=358419&r1=358418&r2=358419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopPredication/basic.ll (original)
+++ llvm/trunk/test/Transforms/LoopPredication/basic.ll Mon Apr 15 08:53:25 2019
@@ -976,11 +976,11 @@ define i32 @two_range_checks(i32* %array
; CHECK-NEXT: [[TMP3:%.*]] = icmp ule i32 [[N]], [[LENGTH_1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp ult i32 0, [[LENGTH_1]]
; CHECK-NEXT: [[TMP5:%.*]] = and i1 [[TMP4]], [[TMP3]]
+; CHECK-NEXT: [[TMP6:%.*]] = and i1 [[TMP2]], [[TMP5]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
-; CHECK-NEXT: [[TMP6:%.*]] = and i1 [[TMP2]], [[TMP5]]
; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP6]], i32 9) [ "deopt"() ]
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_1_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_1:%.*]], i64 [[I_I64]]
@@ -1048,12 +1048,12 @@ define i32 @three_range_checks(i32* %arr
; CHECK-NEXT: [[TMP6:%.*]] = icmp ule i32 [[N]], [[LENGTH_1:%.*]]
; CHECK-NEXT: [[TMP7:%.*]] = icmp ult i32 0, [[LENGTH_1]]
; CHECK-NEXT: [[TMP8:%.*]] = and i1 [[TMP7]], [[TMP6]]
+; CHECK-NEXT: [[TMP9:%.*]] = and i1 [[TMP2]], [[TMP5]]
+; CHECK-NEXT: [[TMP10:%.*]] = and i1 [[TMP9]], [[TMP8]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
-; CHECK-NEXT: [[TMP9:%.*]] = and i1 [[TMP2]], [[TMP5]]
-; CHECK-NEXT: [[TMP10:%.*]] = and i1 [[TMP9]], [[TMP8]]
; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP10]], i32 9) [ "deopt"() ]
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_1_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_1:%.*]], i64 [[I_I64]]
Modified: llvm/trunk/test/Transforms/LoopPredication/widened.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopPredication/widened.ll?rev=358419&r1=358418&r2=358419&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopPredication/widened.ll (original)
+++ llvm/trunk/test/Transforms/LoopPredication/widened.ll Mon Apr 15 08:53:25 2019
@@ -20,6 +20,7 @@ define i64 @iv_wider_type_rc_two_narrow_
; CHECK-NEXT: [[TMP5:%.*]] = icmp ule i32 16, [[TMP4]]
; CHECK-NEXT: [[TMP6:%.*]] = icmp ult i32 [[OFFA]], [[LENGTHA]]
; CHECK-NEXT: [[TMP7:%.*]] = and i1 [[TMP6]], [[TMP5]]
+; CHECK-NEXT: [[TMP8:%.*]] = and i1 [[TMP3]], [[TMP7]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ]
@@ -27,7 +28,6 @@ define i64 @iv_wider_type_rc_two_narrow_
; CHECK-NEXT: [[IV_TRUNC_16:%.*]] = trunc i64 [[IV]] to i16
; CHECK-NEXT: [[INDEXA:%.*]] = add i32 [[IV_TRUNC_32]], [[OFFA]]
; CHECK-NEXT: [[INDEXB:%.*]] = add i16 [[IV_TRUNC_16]], [[OFFB]]
-; CHECK-NEXT: [[TMP8:%.*]] = and i1 [[TMP3]], [[TMP7]]
; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP8]], i32 9) [ "deopt"() ]
; CHECK-NEXT: [[INDEXA_EXT:%.*]] = zext i32 [[INDEXA]] to i64
; CHECK-NEXT: [[ADDRA:%.*]] = getelementptr inbounds i8, i8* [[ARRA]], i64 [[INDEXA_EXT]]
@@ -93,14 +93,14 @@ define i64 @iv_rc_different_types(i32 %o
; CHECK-NEXT: [[TMP11:%.*]] = icmp ule i32 15, [[TMP10]]
; CHECK-NEXT: [[TMP12:%.*]] = icmp ult i32 [[OFFA]], [[LENGTHA]]
; CHECK-NEXT: [[TMP13:%.*]] = and i1 [[TMP12]], [[TMP11]]
+; CHECK-NEXT: [[TMP14:%.*]] = and i1 [[TMP4]], [[TMP8]]
+; CHECK-NEXT: [[TMP15:%.*]] = and i1 [[TMP14]], [[TMP13]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[IV_TRUNC:%.*]] = trunc i64 [[IV]] to i32
; CHECK-NEXT: [[INDEXA:%.*]] = add i32 [[IV_TRUNC]], [[OFFA]]
; CHECK-NEXT: [[INDEXB:%.*]] = add i32 [[IV_TRUNC]], [[OFFB]]
-; CHECK-NEXT: [[TMP14:%.*]] = and i1 [[TMP4]], [[TMP8]]
-; CHECK-NEXT: [[TMP15:%.*]] = and i1 [[TMP14]], [[TMP13]]
; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP15]], i32 9) [ "deopt"() ]
; CHECK-NEXT: [[INDEXA_EXT:%.*]] = zext i32 [[INDEXA]] to i64
; CHECK-NEXT: [[ADDRA:%.*]] = getelementptr inbounds i8, i8* [[ARRA]], i64 [[INDEXA_EXT]]
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