[SCEVPatternMatch] Extend with more matchers

[artagnon]

No description provided.

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Ramkumar Ramachandra (artagnon)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/138836.diff

1 Files Affected:

• (modified) llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h (+40)

diff --git a/llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h b/llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h
index 900f6d0fd05ab..a073f45423dea 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h
@@ -56,6 +56,16 @@ template <typename Class> struct class_match {
   template <typename ITy> bool match(ITy *V) const { return isa<Class>(V); }
 };
 
+inline class_match<const SCEV> m_SCEV() { return class_match<const SCEV>(); }
+
+inline class_match<const SCEVConstant> m_SCEVConstant() {
+  return class_match<const SCEVConstant>();
+}
+
+inline class_match<const SCEVUnknown> m_SCEVUnknown() {
+  return class_match<const SCEVUnknown>();
+}
+
 template <typename Class> struct bind_ty {
   Class *&VR;
 
@@ -91,6 +101,25 @@ struct specificscev_ty {
 /// Match if we have a specific specified SCEV.
 inline specificscev_ty m_Specific(const SCEV *S) { return S; }
 
+template <typename Op0_t> struct cst_match {
+  Op0_t Op0;
+
+  cst_match(Op0_t Op0) : Op0(Op0) {}
+
+  bool match(const SCEV *S) const {
+    assert((isa<SCEVCouldNotCompute>(S) || !S->getType()->isVectorTy()) &&
+           "no vector types expected from SCEVs");
+    auto *C = dyn_cast<SCEVConstant>(S);
+    return C && C->getAPInt() == Op0;
+  }
+};
+
+/// Match an SCEV constant with an APInt.
+inline cst_match<APInt> m_SCEVConstant(const APInt &V) { return V; }
+
+/// Match an SCEV constant with a plain integer.
+inline cst_match<uint64_t> m_SCEVConstant(uint64_t V) { return V; }
+
 /// Match a unary SCEV.
 template <typename SCEVTy, typename Op0_t> struct SCEVUnaryExpr_match {
   Op0_t Op0;
@@ -147,6 +176,17 @@ m_scev_Add(const Op0_t &Op0, const Op1_t &Op1) {
   return m_scev_Binary<SCEVAddExpr>(Op0, Op1);
 }
 
+template <typename Op0_t, typename Op1_t>
+inline SCEVBinaryExpr_match<SCEVMulExpr, Op0_t, Op1_t>
+m_scev_Mul(const Op0_t &Op0, const Op1_t &Op1) {
+  return m_scev_Binary<SCEVMulExpr>(Op0, Op1);
+}
+
+template <typename Op0_t, typename Op1_t>
+inline SCEVBinaryExpr_match<SCEVUDivExpr, Op0_t, Op1_t>
+m_scev_UDiv(const Op0_t &Op0, const Op1_t &Op1) {
+  return m_scev_Binary<SCEVUDivExpr>(Op0, Op1);
+}
 } // namespace SCEVPatternMatch
 } // namespace llvm
 

[fhahn]

This should probably at least contain changes to use each new matcher, to make sure the instantiations work as expected

[artagnon]

This should probably at least contain changes to use each new matcher, to make sure the instantiations work as expected

To actually use this, I first require #138834 merged.

[nikic]

This looks ok, but I think the naming needs more consideration. I think the general intention is to use the same names as PatternMatch but with an m_scev prefix, so I left suggestions accordingly.

[nikic]

LGTM