[PATCH] D129072: [NFC][RISCV] Make the cost calculation of getIntMatCost more clear

[Zixuan Wu via Phabricator via llvm-commits]

zixuan-wu updated this revision to Diff 442481.
zixuan-wu retitled this revision from "[RISCV] Fix the scale of getIntMatCost and also need adjust for getIntImmCost" to "[NFC][RISCV] Make the cost calculation of getIntMatCost more clear".
zixuan-wu edited the summary of this revision.
zixuan-wu added a comment.

The logic of getIntMatCost and getInstSeqCost is correct to be called in different code place. But the logic is not clear. 
So make it clear without still constructing 2 different version of getIntMatCost to reuse the for loop to calculate cost of each chunk.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D129072/new/

https://reviews.llvm.org/D129072

Files:
  llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp


Index: llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp
===================================================================
--- llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp
+++ llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp
@@ -14,7 +14,7 @@
 
 static int getInstSeqCost(RISCVMatInt::InstSeq &Res, bool HasRVC) {
   if (!HasRVC)
-    return Res.size();
+    return Res.size() * 100;
 
   int Cost = 0;
   for (auto Instr : Res) {
@@ -381,7 +381,7 @@
 int getIntMatCost(const APInt &Val, unsigned Size,
                   const FeatureBitset &ActiveFeatures, bool CompressionCost) {
   bool IsRV64 = ActiveFeatures[RISCV::Feature64Bit];
-  bool HasRVC = CompressionCost && ActiveFeatures[RISCV::FeatureStdExtC];
+  bool HasRVC = ActiveFeatures[RISCV::FeatureStdExtC];
   int PlatRegSize = IsRV64 ? 64 : 32;
 
   // Split the constant into platform register sized chunks, and calculate cost
@@ -390,9 +390,16 @@
   for (unsigned ShiftVal = 0; ShiftVal < Size; ShiftVal += PlatRegSize) {
     APInt Chunk = Val.ashr(ShiftVal).sextOrTrunc(PlatRegSize);
     InstSeq MatSeq = generateInstSeq(Chunk.getSExtValue(), ActiveFeatures);
-    Cost += getInstSeqCost(MatSeq, HasRVC);
+    if (CompressionCost)
+      Cost += getInstSeqCost(MatSeq, HasRVC);
+    else
+      Cost += MatSeq.size();
   }
-  return std::max(1, Cost);
+
+  if (CompressionCost)
+    return Cost;
+  else
+    return std::max(1, Cost);
 }
 
 OpndKind Inst::getOpndKind() const {


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