From 81df452d8268ab52c28ef2fb015f161061d3c919 Mon Sep 17 00:00:00 2001
From: Johannes Doerfert <jdoerfert@anl.gov>
Date: Fri, 30 Aug 2019 15:22:28 +0000
Subject: [PATCH] [Attributor] Manifest load/store alignment generally

Summary:
Any pointer could have load/store users not only floating ones so we
move the manifest logic for alignment into the AAAlignImpl class.

Reviewers: uenoku, sstefan1

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66922

llvm-svn: 370479
---
 llvm/lib/Transforms/IPO/Attributor.cpp      | 50 ++++++++++-----------
 llvm/test/Transforms/FunctionAttrs/align.ll |  2 +
 2 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index 05686921a65a..65590644acff 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -2185,30 +2185,6 @@ struct AAAlignImpl : AAAlign {
       takeKnownMaximum(Attr.getValueAsInt());
   }
 
-  // TODO: Provide a helper to determine the implied ABI alignment and check in
-  //       the existing manifest method and a new one for AAAlignImpl that value
-  //       to avoid making the alignment explicit if it did not improve.
-
-  /// See AbstractAttribute::getDeducedAttributes
-  virtual void
-  getDeducedAttributes(LLVMContext &Ctx,
-                       SmallVectorImpl<Attribute> &Attrs) const override {
-    if (getAssumedAlign() > 1)
-      Attrs.emplace_back(Attribute::getWithAlignment(Ctx, getAssumedAlign()));
-  }
-
-  /// See AbstractAttribute::getAsStr().
-  const std::string getAsStr() const override {
-    return getAssumedAlign() ? ("align<" + std::to_string(getKnownAlign()) +
-                                "-" + std::to_string(getAssumedAlign()) + ">")
-                             : "unknown-align";
-  }
-};
-
-/// Align attribute for a floating value.
-struct AAAlignFloating : AAAlignImpl {
-  AAAlignFloating(const IRPosition &IRP) : AAAlignImpl(IRP) {}
-
   /// See AbstractAttribute::manifest(...).
   ChangeStatus manifest(Attributor &A) override {
     ChangeStatus Changed = ChangeStatus::UNCHANGED;
@@ -2235,9 +2211,33 @@ struct AAAlignFloating : AAAlignImpl {
       }
     }
 
-    return AAAlignImpl::manifest(A) | Changed;
+    return AAAlign::manifest(A) | Changed;
   }
 
+  // TODO: Provide a helper to determine the implied ABI alignment and check in
+  //       the existing manifest method and a new one for AAAlignImpl that value
+  //       to avoid making the alignment explicit if it did not improve.
+
+  /// See AbstractAttribute::getDeducedAttributes
+  virtual void
+  getDeducedAttributes(LLVMContext &Ctx,
+                       SmallVectorImpl<Attribute> &Attrs) const override {
+    if (getAssumedAlign() > 1)
+      Attrs.emplace_back(Attribute::getWithAlignment(Ctx, getAssumedAlign()));
+  }
+
+  /// See AbstractAttribute::getAsStr().
+  const std::string getAsStr() const override {
+    return getAssumedAlign() ? ("align<" + std::to_string(getKnownAlign()) +
+                                "-" + std::to_string(getAssumedAlign()) + ">")
+                             : "unknown-align";
+  }
+};
+
+/// Align attribute for a floating value.
+struct AAAlignFloating : AAAlignImpl {
+  AAAlignFloating(const IRPosition &IRP) : AAAlignImpl(IRP) {}
+
   /// See AbstractAttribute::updateImpl(...).
   ChangeStatus updateImpl(Attributor &A) override {
     const DataLayout &DL = A.getDataLayout();
diff --git a/llvm/test/Transforms/FunctionAttrs/align.ll b/llvm/test/Transforms/FunctionAttrs/align.ll
index fd35b6964e05..e3fff44ce234 100644
--- a/llvm/test/Transforms/FunctionAttrs/align.ll
+++ b/llvm/test/Transforms/FunctionAttrs/align.ll
@@ -90,6 +90,8 @@ define internal i8* @f1(i8* readnone %0) local_unnamed_addr #0 {
 ; <label>:3:                                      ; preds = %1
 ; ATTRIBUTOR: %4 = tail call i8* @f2(i8* nonnull align 8 dereferenceable(1) @a1)
   %4 = tail call i8* @f2(i8* nonnull @a1)
+; ATTRIBUTOR: %l = load i8, i8* %4, align 8
+  %l = load i8, i8* %4
   br label %5
 
 ; <label>:5:                                      ; preds = %1, %3