[llvm] c819266 - [Attributor] Improve the Attributor::getAssumedConstant interface

[Johannes Doerfert via llvm-commits]

Author: Johannes Doerfert
Date: 2021-07-22T00:07:55-05:00
New Revision: c819266ecc8fa12e0d567be6b4dd7ea9c4eede87

URL: https://github.com/llvm/llvm-project/commit/c819266ecc8fa12e0d567be6b4dd7ea9c4eede87
DIFF: https://github.com/llvm/llvm-project/commit/c819266ecc8fa12e0d567be6b4dd7ea9c4eede87.diff

LOG: [Attributor] Improve the Attributor::getAssumedConstant interface

Similar to Attributor::getAssumedSimplified we need to allow IRPs
directly to get the right simplification callback (and context).

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/IPO/Attributor.h
    llvm/lib/Transforms/IPO/Attributor.cpp

Removed: 
    


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diff  --git a/llvm/include/llvm/Transforms/IPO/Attributor.h b/llvm/include/llvm/Transforms/IPO/Attributor.h
index 234a384b36bc..01b40ff7cc23 100644
--- a/llvm/include/llvm/Transforms/IPO/Attributor.h
+++ b/llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -1499,11 +1499,16 @@ struct Attributor {
       ToBeDeletedFunctions.insert(&F);
   }
 
-  /// If \p V is assumed to be a constant, return it, if it is unclear yet,
+  /// If \p IRP is assumed to be a constant, return it, if it is unclear yet,
   /// return None, otherwise return `nullptr`.
-  Optional<Constant *> getAssumedConstant(const Value &V,
+  Optional<Constant *> getAssumedConstant(const IRPosition &IRP,
                                           const AbstractAttribute &AA,
                                           bool &UsedAssumedInformation);
+  Optional<Constant *> getAssumedConstant(const Value &V,
+                                          const AbstractAttribute &AA,
+                                          bool &UsedAssumedInformation) {
+    return getAssumedConstant(IRPosition::value(V), AA, UsedAssumedInformation);
+  }
 
   /// If \p V is assumed simplified, return it, if it is unclear yet,
   /// return None, otherwise return `nullptr`.

diff  --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index 87c772167dcd..61659b295f22 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -648,19 +648,19 @@ void IRPosition::verify() {
 }
 
 Optional<Constant *>
-Attributor::getAssumedConstant(const Value &V, const AbstractAttribute &AA,
+Attributor::getAssumedConstant(const IRPosition &IRP,
+                               const AbstractAttribute &AA,
                                bool &UsedAssumedInformation) {
   // First check all callbacks provided by outside AAs. If any of them returns
   // a non-null value that is 
diff erent from the associated value, or None, we
   // assume it's simpliied.
-  IRPosition IRP = IRPosition::value(V, AA.getCallBaseContext());
   for (auto &CB : SimplificationCallbacks[IRP]) {
     Optional<Value *> SimplifiedV = CB(IRP, &AA, UsedAssumedInformation);
     if (!SimplifiedV.hasValue())
       return llvm::None;
-    if (*SimplifiedV && *SimplifiedV != &IRP.getAssociatedValue() &&
-        isa<Constant>(*SimplifiedV))
+    if (isa_and_nonnull<Constant>(*SimplifiedV))
       return cast<Constant>(*SimplifiedV);
+    return nullptr;
   }
   const auto &ValueSimplifyAA =
       getAAFor<AAValueSimplify>(AA, IRP, DepClassTy::NONE);
@@ -674,13 +674,12 @@ Attributor::getAssumedConstant(const Value &V, const AbstractAttribute &AA,
   }
   if (isa_and_nonnull<UndefValue>(SimplifiedV.getValue())) {
     recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL);
-    return UndefValue::get(V.getType());
+    return UndefValue::get(IRP.getAssociatedType());
   }
   Constant *CI = dyn_cast_or_null<Constant>(SimplifiedV.getValue());
-  if (CI && CI->getType() != V.getType()) {
-    // TODO: Check for a save conversion.
-    return nullptr;
-  }
+  if (CI)
+    CI = dyn_cast_or_null<Constant>(
+        AA::getWithType(*CI, *IRP.getAssociatedType()));
   if (CI)
     recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL);
   return CI;
@@ -695,9 +694,7 @@ Attributor::getAssumedSimplified(const IRPosition &IRP,
   // assume it's simpliied.
   for (auto &CB : SimplificationCallbacks[IRP]) {
     Optional<Value *> SimplifiedV = CB(IRP, AA, UsedAssumedInformation);
-    if (!SimplifiedV.hasValue() ||
-        (*SimplifiedV && *SimplifiedV != &IRP.getAssociatedValue()))
-      return SimplifiedV;
+    return SimplifiedV;
   }
 
   // If no high-level/outside simplification occured, use AAValueSimplify.