From 9a100cced74ec58597da5d2d7cd1b83deb1973aa Mon Sep 17 00:00:00 2001
From: Sjoerd Meijer <sjoerd.meijer@arm.com>
Date: Fri, 3 Jun 2016 13:14:19 +0000
Subject: [PATCH] Currently AsmWriterEmiter.cpp (used by tblgen
 -gen-asm-writer) does not consider the Predicates attached to InstAlias when
 generating printAliasInstr. This forces users of printAliasInstr to check
 those predicates beforehand.

This commit adds them in the condition set of the IAPrinter object.

Patch by: Roger Ferrer Ibanez

Differential Revision: http://reviews.llvm.org/D20233

llvm-svn: 271665
---
 utils/TableGen/AsmWriterEmitter.cpp | 36 +++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/utils/TableGen/AsmWriterEmitter.cpp b/utils/TableGen/AsmWriterEmitter.cpp
index b7674a12b44..7aecafe3ece 100644
--- a/utils/TableGen/AsmWriterEmitter.cpp
+++ b/utils/TableGen/AsmWriterEmitter.cpp
@@ -601,7 +601,6 @@ namespace {
 class IAPrinter {
   std::vector<std::string> Conds;
   std::map<StringRef, std::pair<int, int>> OpMap;
-  SmallVector<Record*, 4> ReqFeatures;
 
   std::string Result;
   std::string AsmString;
@@ -648,7 +647,7 @@ public:
   }
 
   void print(raw_ostream &O) {
-    if (Conds.empty() && ReqFeatures.empty()) {
+    if (Conds.empty()) {
       O.indent(6) << "return true;\n";
       return;
     }
@@ -798,6 +797,18 @@ void AsmWriterEmitter::EmitPrintAliasInstruction(raw_ostream &O) {
 
       IAPrinter IAP(CGA.Result->getAsString(), CGA.AsmString);
 
+      std::string Namespace = Target.getName();
+      std::vector<Record *> ReqFeatures;
+      if (PassSubtarget) {
+        // We only consider ReqFeatures predicates if PassSubtarget
+        std::vector<Record *> RF =
+            CGA.TheDef->getValueAsListOfDefs("Predicates");
+        std::copy_if(RF.begin(), RF.end(), std::back_inserter(ReqFeatures),
+                     [](Record *R) {
+                       return R->getValueAsBit("AssemblerMatcherPredicate");
+                     });
+      }
+
       unsigned NumMIOps = 0;
       for (auto &Operand : CGA.ResultOperands)
         NumMIOps += Operand.getMINumOperands();
@@ -902,6 +913,27 @@ void AsmWriterEmitter::EmitPrintAliasInstruction(raw_ostream &O) {
       }
 
       if (CantHandle) continue;
+
+      for (auto I = ReqFeatures.cbegin(); I != ReqFeatures.cend(); I++) {
+        Record *R = *I;
+        std::string AsmCondString = R->getValueAsString("AssemblerCondString");
+
+        // AsmCondString has syntax [!]F(,[!]F)*
+        SmallVector<StringRef, 4> Ops;
+        SplitString(AsmCondString, Ops, ",");
+        assert(!Ops.empty() && "AssemblerCondString cannot be empty");
+
+        for (auto &Op : Ops) {
+          assert(!Op.empty() && "Empty operator");
+          if (Op[0] == '!')
+            Cond = "!STI.getFeatureBits()[" + Namespace + "::" +
+                   Op.substr(1).str() + "]";
+          else
+            Cond = "STI.getFeatureBits()[" + Namespace + "::" + Op.str() + "]";
+          IAP.addCond(Cond);
+        }
+      }
+
       IAPrinterMap[Aliases.first].push_back(std::move(IAP));
     }
   }