[llvm] ff1147c - Revert "Ensure that InstructionCost actually implements a total ordering"
Christopher Tetreault via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 2 12:11:59 PST 2021
Author: Christopher Tetreault
Date: 2021-02-02T12:10:02-08:00
New Revision: ff1147c3635685ba6aefbdc9394300adb5404595
URL: https://github.com/llvm/llvm-project/commit/ff1147c3635685ba6aefbdc9394300adb5404595
DIFF: https://github.com/llvm/llvm-project/commit/ff1147c3635685ba6aefbdc9394300adb5404595.diff
LOG: Revert "Ensure that InstructionCost actually implements a total ordering"
This reverts commit b481cd519e07b3ad2bd3e81c89b0dd8efd68d6bc.
Added:
Modified:
llvm/include/llvm/Support/InstructionCost.h
llvm/unittests/Support/InstructionCostTest.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Support/InstructionCost.h b/llvm/include/llvm/Support/InstructionCost.h
index 7101ed1c9365..fbc898b878bb 100644
--- a/llvm/include/llvm/Support/InstructionCost.h
+++ b/llvm/include/llvm/Support/InstructionCost.h
@@ -146,30 +146,31 @@ class InstructionCost {
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 !(*this < RHS) && !(RHS < *this);
+ return State == RHS.State && Value == RHS.Value;
}
bool operator!=(const InstructionCost &RHS) const { return !(*this == RHS); }
bool operator==(const CostType RHS) const {
- InstructionCost RHS2(RHS);
- return *this == RHS2;
+ return State == Valid && Value == RHS;
}
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); }
diff --git a/llvm/unittests/Support/InstructionCostTest.cpp b/llvm/unittests/Support/InstructionCostTest.cpp
index 2a881a71e2e4..8ba9f990f027 100644
--- a/llvm/unittests/Support/InstructionCostTest.cpp
+++ b/llvm/unittests/Support/InstructionCostTest.cpp
@@ -25,7 +25,6 @@ TEST_F(CostTest, Operators) {
InstructionCost VSix = 6;
InstructionCost IThreeA = InstructionCost::getInvalid(3);
InstructionCost IThreeB = InstructionCost::getInvalid(3);
- InstructionCost ITwo = InstructionCost::getInvalid(2);
InstructionCost TmpCost;
EXPECT_NE(VThree, VNegTwo);
@@ -38,9 +37,6 @@ TEST_F(CostTest, Operators) {
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);
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