Fix integer undefined behavior due to signed left shift overflow in LLVM.

[oota-llvm.git] / lib / Target / TargetInstrInfo.cpp

diff --git a/lib/Target/TargetInstrInfo.cpp b/lib/Target/TargetInstrInfo.cpp
index ad5a9d71da49ff7b5693ca7c005e9c6354461b1f..f1d1d07c38aef048793903f90f9516679825148c 100644 (file)
--- a/lib/Target/TargetInstrInfo.cpp
+++ b/lib/Target/TargetInstrInfo.cpp
@@ -13,44 +13,76 @@
 
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCInstrItineraries.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <cctype>
 using namespace llvm;
 
-TargetInstrInfo::TargetInstrInfo(const TargetInstrDesc* Desc,
-                                 unsigned numOpcodes)
-  : Descriptors(Desc), NumOpcodes(numOpcodes) {
-}
+//===----------------------------------------------------------------------===//
+//  TargetInstrInfo
+//
+// Methods that depend on CodeGen are implemented in
+// TargetInstrInfoImpl.cpp. Invoking them without linking libCodeGen raises a
+// link error.
+// ===----------------------------------------------------------------------===//
 
 TargetInstrInfo::~TargetInstrInfo() {
 }
 
+const TargetRegisterClass*
+TargetInstrInfo::getRegClass(const MCInstrDesc &MCID, unsigned OpNum,
+                             const TargetRegisterInfo *TRI,
+                             const MachineFunction &MF) const {
+  if (OpNum >= MCID.getNumOperands())
+    return 0;
+
+  short RegClass = MCID.OpInfo[OpNum].RegClass;
+  if (MCID.OpInfo[OpNum].isLookupPtrRegClass())
+    return TRI->getPointerRegClass(MF, RegClass);
+
+  // Instructions like INSERT_SUBREG do not have fixed register classes.
+  if (RegClass < 0)
+    return 0;
+
+  // Otherwise just look it up normally.
+  return TRI->getRegClass(RegClass);
+}
+
 /// insertNoop - Insert a noop into the instruction stream at the specified
 /// point.
-void TargetInstrInfo::insertNoop(MachineBasicBlock &MBB, 
+void TargetInstrInfo::insertNoop(MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator MI) const {
   llvm_unreachable("Target didn't implement insertNoop!");
 }
 
+/// Measure the specified inline asm to determine an approximation of its
+/// length.
+/// Comments (which run till the next SeparatorString or newline) do not
+/// count as an instruction.
+/// Any other non-whitespace text is considered an instruction, with
+/// multiple instructions separated by SeparatorString or newlines.
+/// Variable-length instructions are not handled here; this function
+/// may be overloaded in the target code to do that.
+unsigned TargetInstrInfo::getInlineAsmLength(const char *Str,
+                                             const MCAsmInfo &MAI) const {
 
-bool TargetInstrInfo::isUnpredicatedTerminator(const MachineInstr *MI) const {
-  const TargetInstrDesc &TID = MI->getDesc();
-  if (!TID.isTerminator()) return false;
-  
-  // Conditional branch is a special case.
-  if (TID.isBranch() && !TID.isBarrier())
-    return true;
-  if (!TID.isPredicable())
-    return true;
-  return !isPredicated(MI);
-}
 
-/// getRegClass - Get the register class for the operand, handling resolution
-/// of "symbolic" pointer register classes etc.  If this is not a register
-/// operand, this returns null.
-const TargetRegisterClass *
-TargetOperandInfo::getRegClass(const TargetRegisterInfo *TRI) const {
-  if (isLookupPtrRegClass())
-    return TRI->getPointerRegClass(RegClass);
-  return TRI->getRegClass(RegClass);
-}
+  // Count the number of instructions in the asm.
+  bool atInsnStart = true;
+  unsigned Length = 0;
+  for (; *Str; ++Str) {
+    if (*Str == '\n' || strncmp(Str, MAI.getSeparatorString(),
+                                strlen(MAI.getSeparatorString())) == 0)
+      atInsnStart = true;
+    if (atInsnStart && !std::isspace(*Str)) {
+      Length += MAI.getMaxInstLength();
+      atInsnStart = false;
+    }
+    if (atInsnStart && strncmp(Str, MAI.getCommentString(),
+                               strlen(MAI.getCommentString())) == 0)
+      atInsnStart = false;
+  }
 
+  return Length;
+}