[PATCH] D95803: Ensure that InstructionCost actually implements a total ordering
Christopher Tetreault via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 2 11:49:35 PST 2021
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGb481cd519e07: Ensure that InstructionCost actually implements a total ordering (authored by ctetreau).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D95803/new/
https://reviews.llvm.org/D95803
Files:
llvm/include/llvm/Support/InstructionCost.h
llvm/unittests/Support/InstructionCostTest.cpp
Index: llvm/unittests/Support/InstructionCostTest.cpp
===================================================================
--- llvm/unittests/Support/InstructionCostTest.cpp
+++ llvm/unittests/Support/InstructionCostTest.cpp
@@ -25,6 +25,7 @@
InstructionCost VSix = 6;
InstructionCost IThreeA = InstructionCost::getInvalid(3);
InstructionCost IThreeB = InstructionCost::getInvalid(3);
+ InstructionCost ITwo = InstructionCost::getInvalid(2);
InstructionCost TmpCost;
EXPECT_NE(VThree, VNegTwo);
@@ -37,6 +38,9 @@
EXPECT_EQ(VThree - VNegTwo, 5);
EXPECT_EQ(VThree * VNegTwo, -6);
EXPECT_EQ(VSix / VThree, 2);
+ EXPECT_NE(IThreeA, ITwo);
+ EXPECT_LT(ITwo, IThreeA);
+ EXPECT_GT(IThreeA, ITwo);
EXPECT_FALSE(IThreeA.isValid());
EXPECT_EQ(IThreeA.getState(), InstructionCost::Invalid);
Index: llvm/include/llvm/Support/InstructionCost.h
===================================================================
--- llvm/include/llvm/Support/InstructionCost.h
+++ llvm/include/llvm/Support/InstructionCost.h
@@ -146,31 +146,30 @@
return Copy;
}
+ /// For the comparison operators we have chosen to use lexicographical
+ /// ordering where valid costs are always considered to be less than invalid
+ /// costs. This avoids having to add asserts to the comparison operators that
+ /// the states are valid and users can test for validity of the cost
+ /// explicitly.
+ bool operator<(const InstructionCost &RHS) const {
+ return State < RHS.State || Value < RHS.Value;
+ }
+
+ // Implement in terms of operator< to ensure that the two comparisons stay in
+ // sync
bool operator==(const InstructionCost &RHS) const {
- return State == RHS.State && Value == RHS.Value;
+ return !(*this < RHS) && !(RHS < *this);
}
bool operator!=(const InstructionCost &RHS) const { return !(*this == RHS); }
bool operator==(const CostType RHS) const {
- return State == Valid && Value == RHS;
+ InstructionCost RHS2(RHS);
+ return *this == RHS2;
}
bool operator!=(const CostType RHS) const { return !(*this == RHS); }
- /// For the comparison operators we have chosen to use total ordering with
- /// the following rules:
- /// 1. If either of the states != Valid then a lexicographical order is
- /// applied based upon the state.
- /// 2. If both states are valid then order based upon value.
- /// This avoids having to add asserts the comparison operators that the states
- /// are valid and users can test for validity of the cost explicitly.
- bool operator<(const InstructionCost &RHS) const {
- if (State != Valid || RHS.State != Valid)
- return State < RHS.State;
- return Value < RHS.Value;
- }
-
bool operator>(const InstructionCost &RHS) const { return RHS < *this; }
bool operator<=(const InstructionCost &RHS) const { return !(RHS < *this); }
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D95803.320869.patch
Type: text/x-patch
Size: 2861 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210202/c9f9d191/attachment.bin>
More information about the llvm-commits
mailing list