From 4c7b07a66f3d5c14339a6181fa12d060aeb9b18c Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 13 Oct 2006 17:50:07 +0000
Subject: [PATCH] Expose method and ivars for measuring inline asm length
 properly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30934 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Target/TargetAsmInfo.h | 15 +++++++++++++--
 lib/Target/TargetAsmInfo.cpp        | 20 ++++++++++++++++++--
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/include/llvm/Target/TargetAsmInfo.h b/include/llvm/Target/TargetAsmInfo.h
index 930ad902c12..d9ddf06a4fa 100644
--- a/include/llvm/Target/TargetAsmInfo.h
+++ b/include/llvm/Target/TargetAsmInfo.h
@@ -27,7 +27,6 @@ namespace llvm {
   /// TargetAsmInfo - This class is intended to be used as a base class for asm
   /// properties and features specific to the target.
   class TargetAsmInfo {
-  
   protected:
     //===------------------------------------------------------------------===//
     // Properties to be set by the target writer, used to configure asm printer.
@@ -48,6 +47,15 @@ namespace llvm {
     /// NeedsSet - True if target asm can't compute addresses on data
     /// directives.
     bool NeedsSet;                        // Defaults to false.
+    
+    /// MaxInstLength - This is the maximum possible length of an instruction,
+    /// which is needed to compute the size of an inline asm.
+    unsigned MaxInstLength;               // Defaults to 4.
+    
+    /// SeparatorChar - This character, if specified, is used to separate
+    /// instructions from each other when on the same line.  This is used to
+    /// measure inline asm instructions.
+    char SeparatorChar;                   // Defaults to ';'
 
     /// CommentString - This indicates the comment character used by the
     /// assembler.
@@ -261,6 +269,10 @@ namespace llvm {
     TargetAsmInfo();
     virtual ~TargetAsmInfo();
 
+    /// Measure the specified inline asm to determine an approximation of its
+    /// length.
+    unsigned getInlineAsmLength(const char *Str) const;
+    
     //
     // Accessors.
     //
@@ -430,7 +442,6 @@ namespace llvm {
       return DwarfMacInfoSection;
     }
   };
-  
 }
 
 #endif
diff --git a/lib/Target/TargetAsmInfo.cpp b/lib/Target/TargetAsmInfo.cpp
index 79c064c3716..7d463ce572f 100644
--- a/lib/Target/TargetAsmInfo.cpp
+++ b/lib/Target/TargetAsmInfo.cpp
@@ -21,6 +21,8 @@ TargetAsmInfo::TargetAsmInfo() :
   DataSection(".data"),
   AddressSize(4),
   NeedsSet(false),
+  MaxInstLength(4),
+  SeparatorChar(';'),
   CommentString("#"),
   GlobalPrefix(""),
   PrivateGlobalPrefix("."),
@@ -71,8 +73,22 @@ TargetAsmInfo::TargetAsmInfo() :
   DwarfLocSection(".debug_loc"),
   DwarfARangesSection(".debug_aranges"),
   DwarfRangesSection(".debug_ranges"),
-  DwarfMacInfoSection(".debug_macinfo")
-{}
+  DwarfMacInfoSection(".debug_macinfo") {
+}
 
 TargetAsmInfo::~TargetAsmInfo() {
 }
+
+/// Measure the specified inline asm to determine an approximation of its
+/// length.
+unsigned TargetAsmInfo::getInlineAsmLength(const char *Str) const {
+  // Count the number of instructions in the asm.
+  unsigned NumInsts = 0;
+  for (; *Str; ++Str) {
+    if (*Str == '\n' || *Str == SeparatorChar)
+      ++NumInsts;
+  }
+
+  // Multiply by the worst-case length for each instruction.
+  return NumInsts * MaxInstLength;
+}