[PATCH] D125748: [RISCV] Drop notion of "strict" vsetvli compatibility

[Fraser Cormack via Phabricator via llvm-commits]

frasercrmck created this revision.
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With recent fixes to the dataflow in place, we now never pass
Strict=true to isCompatible, so remove the parameter completely.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D125748

Files:
  llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp


Index: llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
+++ llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
@@ -215,14 +215,11 @@
            MaskAgnostic == Other.MaskAgnostic;
   }
 
-  bool hasCompatibleVTYPE(const VSETVLIInfo &Require, bool Strict) const {
+  bool hasCompatibleVTYPE(const VSETVLIInfo &Require) const {
     // Simple case, see if full VTYPE matches.
     if (hasSameVTYPE(Require))
       return true;
 
-    if (Strict)
-      return false;
-
     // If this is a mask reg operation, it only cares about VLMAX.
     // FIXME: Mask reg operations are probably ok if "this" VLMAX is larger
     // than "Require".
@@ -238,7 +235,7 @@
   // Determine whether the vector instructions requirements represented by
   // Require are compatible with the previous vsetvli instruction represented
   // by this.
-  bool isCompatible(const VSETVLIInfo &Require, bool Strict) const {
+  bool isCompatible(const VSETVLIInfo &Require) const {
     assert(isValid() && Require.isValid() &&
            "Can't compare invalid VSETVLIInfos");
     assert(!Require.SEWLMULRatioOnly &&
@@ -253,16 +250,14 @@
 
     // If the instruction doesn't need an AVLReg and the SEW matches, consider
     // it compatible.
-    if (!Strict && Require.hasAVLReg() &&
-        Require.AVLReg == RISCV::NoRegister) {
+    if (Require.hasAVLReg() && Require.AVLReg == RISCV::NoRegister)
       if (SEW == Require.SEW)
         return true;
-    }
 
     // For vmv.s.x and vfmv.s.f, there is only two behaviors, VL = 0 and VL > 0.
     // So it's compatible when we could make sure that both VL be the same
     // situation.
-    if (!Strict && Require.ScalarMovOp && Require.hasAVLImm() &&
+    if (Require.ScalarMovOp && Require.hasAVLImm() &&
         ((hasNonZeroAVL() && Require.hasNonZeroAVL()) ||
          (hasZeroAVL() && Require.hasZeroAVL())) &&
         hasSameSEW(Require) && hasSamePolicy(Require))
@@ -272,13 +267,9 @@
     if (!hasSameAVL(Require))
       return false;
 
-    if (hasCompatibleVTYPE(Require, Strict))
+    if (hasCompatibleVTYPE(Require))
       return true;
 
-    // Strict matches must ensure a full VTYPE match.
-    if (Strict)
-      return false;
-
     // Store instructions don't use the policy fields.
     // TODO: Move into hasCompatibleVTYPE?
     if (Require.StoreOp && VLMul == Require.VLMul && SEW == Require.SEW)
@@ -706,7 +697,7 @@
 
 bool RISCVInsertVSETVLI::needVSETVLI(const VSETVLIInfo &Require,
                                      const VSETVLIInfo &CurInfo) {
-  if (CurInfo.isCompatible(Require, /*Strict*/ false))
+  if (CurInfo.isCompatible(Require))
     return false;
 
   // We didn't find a compatible value. If our AVL is a virtual register,
@@ -715,7 +706,7 @@
   // VSETVLI here.
   if (!CurInfo.isUnknown() && Require.hasAVLReg() &&
       Require.getAVLReg().isVirtual() && !CurInfo.hasSEWLMULRatioOnly() &&
-      CurInfo.hasCompatibleVTYPE(Require, /*Strict*/ false)) {
+      CurInfo.hasCompatibleVTYPE(Require)) {
     if (MachineInstr *DefMI = MRI->getVRegDef(Require.getAVLReg())) {
       if (isVectorConfigInstr(*DefMI)) {
         VSETVLIInfo DefInfo = getInfoForVSETVLI(*DefMI);
@@ -1046,8 +1037,7 @@
     const BlockData &PBBInfo = BlockInfo[PBB->getNumber()];
     // If the exit from the predecessor has the VTYPE we are looking for
     // we might be able to avoid a VSETVLI.
-    if (PBBInfo.Exit.isUnknown() ||
-        !PBBInfo.Exit.hasCompatibleVTYPE(Require, /*Strict*/ false))
+    if (PBBInfo.Exit.isUnknown() || !PBBInfo.Exit.hasCompatibleVTYPE(Require))
       return true;
 
     // We need the PHI input to the be the output of a VSET(I)VLI.


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