From 63c8b14ddc15147f443806408db6459183af26c1 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 10 Mar 2009 05:39:21 +0000
Subject: [PATCH] Expand %= into ${:uid} so that the code generator emits a
 unique ID for the asm.  This allows us to properly handle the case when an
 optimizer duplicates the asm, such as here:

void bar() {
  int i;
  for (i = 0; i < 3; ++i)
    asm("foo %=" : : "r"(0));
}

we now produce:

_bar:
	xorl	%eax, %eax
	## InlineAsm Start
	foo 0
	## InlineAsm End
	## InlineAsm Start
	foo 1
	## InlineAsm End
	## InlineAsm Start
	foo 2
	## InlineAsm End
	ret

instead of:

_bar:
	xorl	%eax, %eax
	## InlineAsm Start
	foo 1
	## InlineAsm End
	## InlineAsm Start
	foo 1
	## InlineAsm End
	## InlineAsm Start
	foo 1
	## InlineAsm End
	ret

This also fixes a fixme by eliminating a static.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66528 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGStmt.cpp | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 3fd6526777..5989dcc068 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -714,10 +714,6 @@ static std::string ConvertAsmString(const AsmStmt& S, bool &Failed) {
   
   unsigned NumOperands = S.getNumOutputs() + S.getNumInputs();
   
-  // FIXME: Static counters are not thread safe or reproducible.
-  static unsigned AsmCounter = 0;
-  AsmCounter++;
-  
   while (*Start) {
     switch (*Start) {
     default:
@@ -729,10 +725,8 @@ static std::string ConvertAsmString(const AsmStmt& S, bool &Failed) {
     case '%':
       // Escaped character
       Start++;
-      if (!*Start) {
-        // FIXME: This should be caught during Sema.
-        assert(0 && "Trailing '%' in asm string.");
-      }
+      // FIXME: This should be caught during Sema.
+      assert(*Start && "Trailing '%' in asm string.");
       
       char EscapedChar = *Start;
       if (EscapedChar == '%') {
@@ -740,7 +734,7 @@ static std::string ConvertAsmString(const AsmStmt& S, bool &Failed) {
         Result += '%';
       } else if (EscapedChar == '=') {
         // Generate an unique ID.
-        Result += llvm::utostr(AsmCounter);
+        Result += "${:uid}";
       } else if (isdigit(EscapedChar)) {
         // %n - Assembler operand n
         char *End;
@@ -823,8 +817,7 @@ static std::string ConvertAsmString(const AsmStmt& S, bool &Failed) {
 static std::string SimplifyConstraint(const char* Constraint,
                                       TargetInfo &Target,
                                       const std::string *OutputNamesBegin = 0,
-                                      const std::string *OutputNamesEnd = 0)
-{
+                                      const std::string *OutputNamesEnd = 0) {
   std::string Result;
   
   while (*Constraint) {
@@ -862,8 +855,7 @@ static std::string SimplifyConstraint(const char* Constraint,
 llvm::Value* CodeGenFunction::EmitAsmInput(const AsmStmt &S,
                                            TargetInfo::ConstraintInfo Info, 
                                            const Expr *InputExpr,
-                                           std::string &ConstraintStr)
-{
+                                           std::string &ConstraintStr) {
   llvm::Value *Arg;
   if ((Info & TargetInfo::CI_AllowsRegister) ||
       !(Info & TargetInfo::CI_AllowsMemory)) { 
-- 
2.40.0