[mips] [IAS] Restore STI.FeatureBits in .set pop.

Summary:
Only restoring AvailableFeatures is not enough and will lead to buggy behaviour.
For example, if we have a feature enabled and we ".set pop", the next time we try
to ".set" that feature nothing will happen because the "!(STI.getFeatureBits()[Feature])"
check will be false, because we didn't restore STI.FeatureBits.

In order to fix this, we need to make MipsAssemblerOptions remember the STI.FeatureBits
instead of the AvailableFeatures and then regenerate AvailableFeatures each time we ".set pop".
This is because, AFAIK, there is no way to convert from AvailableFeatures back to STI.FeatureBits,
but the reverse is possible by using ComputeAvailableFeatures(STI.FeatureBits).

I also moved the updating of AssemblerOptions inside the "if" statement in
setFeatureBits() and clearFeatureBits(), as there is no reason to update if
nothing changes.

Reviewers: dsanders, mkuper

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9156

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239144 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCSubtargetInfo.h b/include/llvm/MC/MCSubtargetInfo.h
index 1778a6d13fb86205cd06dfe931afb51e7e820e19..d25f5d92a8c15024f9a7467ed1168c4f7a03d72a 100644 (file)
--- a/include/llvm/MC/MCSubtargetInfo.h
+++ b/include/llvm/MC/MCSubtargetInfo.h
@@ -73,7 +73,9 @@ public:
 
   /// setFeatureBits - Set the feature bits.
   ///
-  void setFeatureBits(FeatureBitset& FeatureBits_) { FeatureBits = FeatureBits_; }
+  void setFeatureBits(const FeatureBitset &FeatureBits_) {
+    FeatureBits = FeatureBits_;
+  }
 
   /// InitMCProcessorInfo - Set or change the CPU (optionally supplemented with
   /// feature string). Recompute feature bits and scheduling model.

diff --git a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index 0d08138f8a94725e573fbb398b120f6c49236d5a..98d413ca4fe444ae39f6f963a5a54be75d9f6b40 100644 (file)
--- a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -43,7 +43,7 @@ class MCInstrInfo;
 namespace {
 class MipsAssemblerOptions {
 public:
-  MipsAssemblerOptions(uint64_t Features_) : 
+  MipsAssemblerOptions(const FeatureBitset &Features_) :
     ATReg(1), Reorder(true), Macro(true), Features(Features_) {}
 
   MipsAssemblerOptions(const MipsAssemblerOptions *Opts) {
@@ -70,8 +70,8 @@ public:
   void setMacro() { Macro = true; }
   void setNoMacro() { Macro = false; }
 
-  uint64_t getFeatures() const { return Features; }
-  void setFeatures(uint64_t Features_) { Features = Features_; }
+  const FeatureBitset &getFeatures() const { return Features; }
+  void setFeatures(const FeatureBitset &Features_) { Features = Features_; }
 
   // Set of features that are either architecture features or referenced
   // by them (e.g.: FeatureNaN2008 implied by FeatureMips32r6).
@@ -84,7 +84,7 @@ private:
   unsigned ATReg;
   bool Reorder;
   bool Macro;
-  uint64_t Features;
+  FeatureBitset Features;
 };
 }
 
@@ -327,23 +327,23 @@ class MipsAsmParser : public MCTargetAsmParser {
     STI.setFeatureBits(FeatureBits);
     setAvailableFeatures(
         ComputeAvailableFeatures(STI.ToggleFeature(ArchFeature)));
-    AssemblerOptions.back()->setFeatures(getAvailableFeatures());
+    AssemblerOptions.back()->setFeatures(STI.getFeatureBits());
   }
 
   void setFeatureBits(uint64_t Feature, StringRef FeatureString) {
     if (!(STI.getFeatureBits()[Feature])) {
       setAvailableFeatures(
           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
+      AssemblerOptions.back()->setFeatures(STI.getFeatureBits());
     }
-    AssemblerOptions.back()->setFeatures(getAvailableFeatures());
   }
 
   void clearFeatureBits(uint64_t Feature, StringRef FeatureString) {
     if (STI.getFeatureBits()[Feature]) {
       setAvailableFeatures(
           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
+      AssemblerOptions.back()->setFeatures(STI.getFeatureBits());
     }
-    AssemblerOptions.back()->setFeatures(getAvailableFeatures());
   }
 
 public:
@@ -369,11 +369,11 @@ public:
     
     // Remember the initial assembler options. The user can not modify these.
     AssemblerOptions.push_back(
-                     make_unique<MipsAssemblerOptions>(getAvailableFeatures()));
+                     make_unique<MipsAssemblerOptions>(STI.getFeatureBits()));
     
     // Create an assembler options environment for the user to modify.
     AssemblerOptions.push_back(
-                     make_unique<MipsAssemblerOptions>(getAvailableFeatures()));
+                     make_unique<MipsAssemblerOptions>(STI.getFeatureBits()));
 
     getTargetStreamer().updateABIInfo(*this);
 
@@ -3603,7 +3603,9 @@ bool MipsAsmParser::parseSetPopDirective() {
     return reportParseError(Loc, ".set pop with no .set push");
 
   AssemblerOptions.pop_back();
-  setAvailableFeatures(AssemblerOptions.back()->getFeatures());
+  setAvailableFeatures(
+      ComputeAvailableFeatures(AssemblerOptions.back()->getFeatures()));
+  STI.setFeatureBits(AssemblerOptions.back()->getFeatures());
 
   getTargetStreamer().emitDirectiveSetPop();
   return false;
@@ -3673,7 +3675,9 @@ bool MipsAsmParser::parseSetMips0Directive() {
     return reportParseError("unexpected token, expected end of statement");
 
   // Reset assembler options to their initial values.
-  setAvailableFeatures(AssemblerOptions.front()->getFeatures());
+  setAvailableFeatures(
+      ComputeAvailableFeatures(AssemblerOptions.front()->getFeatures()));
+  STI.setFeatureBits(AssemblerOptions.front()->getFeatures());
   AssemblerOptions.back()->setFeatures(AssemblerOptions.front()->getFeatures());
 
   getTargetStreamer().emitDirectiveSetMips0();

diff --git a/test/MC/Mips/set-push-pop-directives-bad.s b/test/MC/Mips/set-push-pop-directives-bad.s
index 53d8b2308153fb61020158bd0e681d74485c2c97..8994eea1c8bbeca5a1fa4127f4bdd6b3ec867911 100644 (file)
--- a/test/MC/Mips/set-push-pop-directives-bad.s
+++ b/test/MC/Mips/set-push-pop-directives-bad.s
@@ -12,3 +12,12 @@
 # CHECK: :[[@LINE-1]]:19: error: unexpected token, expected end of statement
         .set pop bar
 # CHECK: :[[@LINE-1]]:18: error: unexpected token, expected end of statement
+
+        .set hardfloat
+        .set push
+        .set softfloat
+        add.s $f2, $f2, $f2
+# CHECK: :[[@LINE-1]]:9: error: instruction requires a CPU feature not currently enabled
+        .set pop
+        add.s $f2, $f2, $f2
+# CHECK-NOT: :[[@LINE-1]]:9: error: instruction requires a CPU feature not currently enabled

diff --git a/test/MC/Mips/set-push-pop-directives.s b/test/MC/Mips/set-push-pop-directives.s
index 5f55b7c7e4d305c1e854a2e825c23c6e177dcf0a..3a0b2aecc58745d79cc7849d3ce660d67a2638cd 100644 (file)
--- a/test/MC/Mips/set-push-pop-directives.s
+++ b/test/MC/Mips/set-push-pop-directives.s
@@ -51,3 +51,20 @@
 # CHECK:  b        1336
 # CHECK:  nop
 # CHECK:  addvi.b  $w15, $w13, 18
+
+    .set push
+    .set dsp
+    lbux    $7, $10($11)
+    .set pop
+
+    .set push
+    .set dsp
+    lbux    $7, $10($11)
+# CHECK-NOT: :[[@LINE-1]]:5: error: instruction requires a CPU feature not currently enabled
+    .set pop
+
+    .set push
+    .set dsp
+    lbux    $7, $10($11)
+# CHECK-NOT: :[[@LINE-1]]:5: error: instruction requires a CPU feature not currently enabled
+    .set pop