[llvm] 3b8a1d5 - NFC: Migrate SpeculativeExecution to work on InstructionCost

[Sander de Smalen via llvm-commits]

Author: Sander de Smalen
Date: 2021-02-01T12:13:23Z
New Revision: 3b8a1d581e6e1623d046b8b8da577ec4d42a544c

URL: https://github.com/llvm/llvm-project/commit/3b8a1d581e6e1623d046b8b8da577ec4d42a544c
DIFF: https://github.com/llvm/llvm-project/commit/3b8a1d581e6e1623d046b8b8da577ec4d42a544c.diff

LOG: NFC: Migrate SpeculativeExecution to work on InstructionCost

This patch migrates cost values and arithmetic to work on InstructionCost.
When the interfaces to TargetTransformInfo are changed, any InstructionCost
state will propagate naturally.

See this patch for the introduction of the type: https://reviews.llvm.org/D91174
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2020-November/146408.html

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D95356

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/SpeculativeExecution.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/SpeculativeExecution.cpp b/llvm/lib/Transforms/Scalar/SpeculativeExecution.cpp
index c78185f2a6ad..ff9132206231 100644
--- a/llvm/lib/Transforms/Scalar/SpeculativeExecution.cpp
+++ b/llvm/lib/Transforms/Scalar/SpeculativeExecution.cpp
@@ -210,8 +210,8 @@ bool SpeculativeExecutionPass::runOnBasicBlock(BasicBlock &B) {
   return false;
 }
 
-static unsigned ComputeSpeculationCost(const Instruction *I,
-                                       const TargetTransformInfo &TTI) {
+static InstructionCost ComputeSpeculationCost(const Instruction *I,
+                                              const TargetTransformInfo &TTI) {
   switch (Operator::getOpcode(I)) {
     case Instruction::GetElementPtr:
     case Instruction::Add:
@@ -255,7 +255,8 @@ static unsigned ComputeSpeculationCost(const Instruction *I,
       return TTI.getUserCost(I, TargetTransformInfo::TCK_SizeAndLatency);
 
     default:
-      return UINT_MAX; // Disallow anything not explicitly listed.
+      return InstructionCost::getInvalid(); // Disallow anything not explicitly
+                                            // listed.
   }
 }
 
@@ -288,11 +289,11 @@ bool SpeculativeExecutionPass::considerHoistingFromTo(
     return true;
   };
 
-  unsigned TotalSpeculationCost = 0;
+  InstructionCost TotalSpeculationCost = 0;
   unsigned NotHoistedInstCount = 0;
   for (const auto &I : FromBlock) {
-    const unsigned Cost = ComputeSpeculationCost(&I, *TTI);
-    if (Cost != UINT_MAX && isSafeToSpeculativelyExecute(&I) &&
+    const InstructionCost Cost = ComputeSpeculationCost(&I, *TTI);
+    if (Cost.isValid() && isSafeToSpeculativelyExecute(&I) &&
         AllPrecedingUsesFromBlockHoisted(&I)) {
       TotalSpeculationCost += Cost;
       if (TotalSpeculationCost > SpecExecMaxSpeculationCost)