[llvm] 897bdca - [ConstantRange] Add API for intrinsics (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2020-07-29T22:16:27+02:00
New Revision: 897bdca4b81dff200714a5b1cb22b20e9c4c4594

URL: https://github.com/llvm/llvm-project/commit/897bdca4b81dff200714a5b1cb22b20e9c4c4594
DIFF: https://github.com/llvm/llvm-project/commit/897bdca4b81dff200714a5b1cb22b20e9c4c4594.diff

LOG: [ConstantRange] Add API for intrinsics (NFC)

This adds a common API for compute constant ranges of intrinsics.
The intention here is that
a) we can reuse the same code across different passes that handle
   constant ranges, i.e. this can be reused in SCCP
b) we only have to add knowledge about supported intrinsics to
   ConstantRange, not any consumers.

Differential Revision: https://reviews.llvm.org/D84587

Added: 
    

Modified: 
    llvm/include/llvm/IR/ConstantRange.h
    llvm/lib/Analysis/LazyValueInfo.cpp
    llvm/lib/IR/ConstantRange.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/IR/ConstantRange.h b/llvm/include/llvm/IR/ConstantRange.h
index 8ecb9aa0ce02..a027292ea43f 100644
--- a/llvm/include/llvm/IR/ConstantRange.h
+++ b/llvm/include/llvm/IR/ConstantRange.h
@@ -150,6 +150,14 @@ class LLVM_NODISCARD ConstantRange {
                                              const APInt &Other,
                                              unsigned NoWrapKind);
 
+  /// Returns true if ConstantRange calculations are supported for intrinsic
+  /// with \p IntrinsicID.
+  static bool isIntrinsicSupported(Intrinsic::ID IntrinsicID);
+
+  /// Compute range of intrinsic result for the given operand ranges.
+  static ConstantRange intrinsic(Intrinsic::ID IntrinsicID,
+                                 ArrayRef<ConstantRange> Ops);
+
   /// Set up \p Pred and \p RHS such that
   /// ConstantRange::makeExactICmpRegion(Pred, RHS) == *this.  Return true if
   /// successful.

diff  --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index 34cc81c4bf2a..d326a442051a 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -400,8 +400,6 @@ class LazyValueInfoImpl {
                                                     BasicBlock *BB);
   Optional<ValueLatticeElement> solveBlockValueOverflowIntrinsic(
       WithOverflowInst *WO, BasicBlock *BB);
-  Optional<ValueLatticeElement> solveBlockValueSaturatingIntrinsic(
-      SaturatingInst *SI, BasicBlock *BB);
   Optional<ValueLatticeElement> solveBlockValueIntrinsic(IntrinsicInst *II,
                                                          BasicBlock *BB);
   Optional<ValueLatticeElement> solveBlockValueExtractValue(
@@ -1035,43 +1033,24 @@ LazyValueInfoImpl::solveBlockValueOverflowIntrinsic(WithOverflowInst *WO,
       });
 }
 
-Optional<ValueLatticeElement>
-LazyValueInfoImpl::solveBlockValueSaturatingIntrinsic(SaturatingInst *SI,
-                                                      BasicBlock *BB) {
-  switch (SI->getIntrinsicID()) {
-  case Intrinsic::uadd_sat:
-    return solveBlockValueBinaryOpImpl(
-        SI, BB, [](const ConstantRange &CR1, const ConstantRange &CR2) {
-          return CR1.uadd_sat(CR2);
-        });
-  case Intrinsic::usub_sat:
-    return solveBlockValueBinaryOpImpl(
-        SI, BB, [](const ConstantRange &CR1, const ConstantRange &CR2) {
-          return CR1.usub_sat(CR2);
-        });
-  case Intrinsic::sadd_sat:
-    return solveBlockValueBinaryOpImpl(
-        SI, BB, [](const ConstantRange &CR1, const ConstantRange &CR2) {
-          return CR1.sadd_sat(CR2);
-        });
-  case Intrinsic::ssub_sat:
-    return solveBlockValueBinaryOpImpl(
-        SI, BB, [](const ConstantRange &CR1, const ConstantRange &CR2) {
-          return CR1.ssub_sat(CR2);
-        });
-  default:
-    llvm_unreachable("All llvm.sat intrinsic are handled.");
-  }
-}
-
 Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueIntrinsic(
     IntrinsicInst *II, BasicBlock *BB) {
-  if (auto *SI = dyn_cast<SaturatingInst>(II))
-    return solveBlockValueSaturatingIntrinsic(SI, BB);
+  if (!ConstantRange::isIntrinsicSupported(II->getIntrinsicID())) {
+    LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()
+                      << "' - overdefined (unknown intrinsic).\n");
+    return ValueLatticeElement::getOverdefined();
+  }
 
-  LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()
-                    << "' - overdefined (unknown intrinsic).\n");
-  return ValueLatticeElement::getOverdefined();
+  SmallVector<ConstantRange, 2> OpRanges;
+  for (Value *Op : II->args()) {
+    Optional<ConstantRange> Range = getRangeFor(Op, II, BB);
+    if (!Range)
+      return None;
+    OpRanges.push_back(*Range);
+  }
+
+  return ValueLatticeElement::getRange(
+      ConstantRange::intrinsic(II->getIntrinsicID(), OpRanges));
 }
 
 Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueExtractValue(

diff  --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index eabaaa203927..26cff911cd67 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -26,6 +26,7 @@
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instruction.h"
+#include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/Support/Compiler.h"
@@ -835,6 +836,35 @@ ConstantRange ConstantRange::overflowingBinaryOp(Instruction::BinaryOps BinOp,
   }
 }
 
+bool ConstantRange::isIntrinsicSupported(Intrinsic::ID IntrinsicID) {
+  switch (IntrinsicID) {
+  case Intrinsic::uadd_sat:
+  case Intrinsic::usub_sat:
+  case Intrinsic::sadd_sat:
+  case Intrinsic::ssub_sat:
+    return true;
+  default:
+    return false;
+  }
+}
+
+ConstantRange ConstantRange::intrinsic(Intrinsic::ID IntrinsicID,
+                                       ArrayRef<ConstantRange> Ops) {
+  switch (IntrinsicID) {
+  case Intrinsic::uadd_sat:
+    return Ops[0].uadd_sat(Ops[1]);
+  case Intrinsic::usub_sat:
+    return Ops[0].usub_sat(Ops[1]);
+  case Intrinsic::sadd_sat:
+    return Ops[0].sadd_sat(Ops[1]);
+  case Intrinsic::ssub_sat:
+    return Ops[0].ssub_sat(Ops[1]);
+  default:
+    assert(!isIntrinsicSupported(IntrinsicID) && "Shouldn't be supported");
+    llvm_unreachable("Unsupported intrinsic");
+  }
+}
+
 ConstantRange
 ConstantRange::add(const ConstantRange &Other) const {
   if (isEmptySet() || Other.isEmptySet())