[PATCH] D34436: [InlineCost] Do not take INT_MAX when Cost is negative
Jun Bum Lim via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 20 18:16:23 PDT 2017
junbuml created this revision.
Herald added subscribers: eraman, javed.absar, mcrosier.
visitSwitchInst should not take INT_MAX when Cost is negative. Instead of INT_MAX , we also use a valid upperbound cost when overflow occurs in Cost.
https://reviews.llvm.org/D34436
Files:
lib/Analysis/InlineCost.cpp
test/Transforms/Inline/AArch64/switch.ll
Index: test/Transforms/Inline/AArch64/switch.ll
===================================================================
--- test/Transforms/Inline/AArch64/switch.ll
+++ test/Transforms/Inline/AArch64/switch.ll
@@ -121,3 +121,40 @@
ret i32 %r
}
+
+define internal i32 @callee_negativeCost(i32 %t) {
+entry:
+ switch i32 %t, label %sw.default [
+ i32 1, label %sw.bb
+ i32 0, label %sw.bb1
+ i32 42, label %sw.bb2
+ i32 43, label %sw.bb3
+ ]
+
+sw.bb: ; preds = %entry
+ br label %cleanup
+
+sw.bb1: ; preds = %entry
+ br label %cleanup
+
+sw.bb2: ; preds = %entry
+ br label %cleanup
+
+sw.bb3: ; preds = %entry
+ br label %cleanup
+
+sw.default: ; preds = %entry
+ br label %cleanup
+
+cleanup: ; preds = %sw.default, %sw.bb3, %sw.bb2, %sw.bb1, %sw.bb
+ %retval.0 = phi i32 [ 1, %sw.default ], [ 3, %sw.bb3 ], [ 2, %sw.bb2 ], [ 0, %sw.bb1 ], [ 0, %sw.bb ]
+ ret i32 %retval.0
+}
+
+define i32 @caller_negativeCost(i32 %t) {
+; CHECK-LABEL: @caller_negativeCost(
+; CHECK-NOT: call i32 @callee_negativeCost
+entry:
+ %call = call i32 @callee_negativeCost(i32 %t)
+ ret i32 %call
+}
Index: lib/Analysis/InlineCost.cpp
===================================================================
--- lib/Analysis/InlineCost.cpp
+++ lib/Analysis/InlineCost.cpp
@@ -1022,12 +1022,15 @@
// inlining those. It will prevent inlining in cases where the optimization
// does not (yet) fire.
+ // Maximum valid cost increased in this function.
+ int CostUpperBound = INT_MAX - InlineConstants::InstrCost - 1;
+
// Exit early for a large switch, assuming one case needs at least one
// instruction.
// FIXME: This is not true for a bit test, but ignore such case for now to
// save compile-time.
int64_t CostLowerBound =
- std::min((int64_t)INT_MAX,
+ std::min((int64_t)CostUpperBound,
(int64_t)SI.getNumCases() * InlineConstants::InstrCost + Cost);
if (CostLowerBound > Threshold) {
@@ -1044,7 +1047,8 @@
if (JumpTableSize) {
int64_t JTCost = (int64_t)JumpTableSize * InlineConstants::InstrCost +
4 * InlineConstants::InstrCost;
- Cost = std::min((int64_t)INT_MAX, JTCost + Cost);
+
+ Cost = std::min((int64_t)CostUpperBound, JTCost + Cost);
return false;
}
@@ -1068,10 +1072,12 @@
Cost += NumCaseCluster * 2 * InlineConstants::InstrCost;
return false;
}
- int64_t ExpectedNumberOfCompare = 3 * (uint64_t)NumCaseCluster / 2 - 1;
- uint64_t SwitchCost =
+
+ int64_t ExpectedNumberOfCompare = 3 * (int64_t)NumCaseCluster / 2 - 1;
+ int64_t SwitchCost =
ExpectedNumberOfCompare * 2 * InlineConstants::InstrCost;
- Cost = std::min((uint64_t)INT_MAX, SwitchCost + Cost);
+
+ Cost = std::min((int64_t)CostUpperBound, SwitchCost + Cost);
return false;
}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D34436.103311.patch
Type: text/x-patch
Size: 3035 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170621/a410f45a/attachment.bin>
More information about the llvm-commits
mailing list