svn commit: r318655 - in head/contrib/llvm: include/llvm/MC lib/MC lib/Target/ARM/MCTargetDesc

[Dimitry Andric]

Author: dim
Date: Mon May 22 16:16:48 2017
New Revision: 318655
URL: https://svnweb.freebsd.org/changeset/base/318655

Log:
  Pull in r302416 from upstream llvm trunk (by Martin Storsjö):
  
    [ARM] Clear the constant pool cache on explicit .ltorg directives
  
    Multiple ldr pseudoinstructions with the same constant value will
    reuse the same constant pool entry. However, if the constant pool is
    explicitly flushed with a .ltorg directive, we should not try to
    reference constants in the previous pool any longer, since they may
    be out of range.
  
    This fixes assembling hand-written assembler source which repeatedly
    loads the same constant value, across a binary size larger than the
    pc-relative fixup range for ldr instructions (4096 bytes). Such
    assembler source already uses explicit .ltorg instructions to emit
    constant pools with regular intervals. However if we try to reuse
    constants emitted in earlier pools, they end up out of range.
  
    This makes the output of the testcase match what binutils gas does
    (prior to this patch, it would fail to assemble).
  
    Differential Revision: https://reviews.llvm.org/D32847
  
  This should fix "out of range pc-relative fixup value" errors, when
  compiling certain ARM inline assembly for www/webkit-gtk[23].
  
  Reported by:	mmel
  MFC after:	3 days

Modified:
  head/contrib/llvm/include/llvm/MC/ConstantPools.h
  head/contrib/llvm/lib/MC/ConstantPools.cpp
  head/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp

Modified: head/contrib/llvm/include/llvm/MC/ConstantPools.h
==============================================================================
--- head/contrib/llvm/include/llvm/MC/ConstantPools.h	Mon May 22 16:13:30 2017	(r318654)
+++ head/contrib/llvm/include/llvm/MC/ConstantPools.h	Mon May 22 16:16:48 2017	(r318655)
@@ -60,6 +60,8 @@ public:
 
   // Return true if the constant pool is empty
   bool empty();
+
+  void clearCache();
 };
 
 class AssemblerConstantPools {
@@ -83,6 +85,7 @@ class AssemblerConstantPools {
 public:
   void emitAll(MCStreamer &Streamer);
   void emitForCurrentSection(MCStreamer &Streamer);
+  void clearCacheForCurrentSection(MCStreamer &Streamer);
   const MCExpr *addEntry(MCStreamer &Streamer, const MCExpr *Expr,
                          unsigned Size, SMLoc Loc);
 

Modified: head/contrib/llvm/lib/MC/ConstantPools.cpp
==============================================================================
--- head/contrib/llvm/lib/MC/ConstantPools.cpp	Mon May 22 16:13:30 2017	(r318654)
+++ head/contrib/llvm/lib/MC/ConstantPools.cpp	Mon May 22 16:16:48 2017	(r318655)
@@ -54,6 +54,10 @@ const MCExpr *ConstantPool::addEntry(con
 
 bool ConstantPool::empty() { return Entries.empty(); }
 
+void ConstantPool::clearCache() {
+  CachedEntries.clear();
+}
+
 //
 // AssemblerConstantPools implementation
 //
@@ -95,6 +99,13 @@ void AssemblerConstantPools::emitForCurr
   }
 }
 
+void AssemblerConstantPools::clearCacheForCurrentSection(MCStreamer &Streamer) {
+  MCSection *Section = Streamer.getCurrentSectionOnly();
+  if (ConstantPool *CP = getConstantPool(Section)) {
+    CP->clearCache();
+  }
+}
+
 const MCExpr *AssemblerConstantPools::addEntry(MCStreamer &Streamer,
                                                const MCExpr *Expr,
                                                unsigned Size, SMLoc Loc) {

Modified: head/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp
==============================================================================
--- head/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp	Mon May 22 16:13:30 2017	(r318654)
+++ head/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp	Mon May 22 16:16:48 2017	(r318655)
@@ -33,6 +33,7 @@ const MCExpr *ARMTargetStreamer::addCons
 
 void ARMTargetStreamer::emitCurrentConstantPool() {
   ConstantPools->emitForCurrentSection(Streamer);
+  ConstantPools->clearCacheForCurrentSection(Streamer);
 }
 
 // finish() - write out any non-empty assembler constant pools.