Add support for having different alignment for objects on call frames.

The x86-64 ABI states that objects passed on the stack have
8 byte alignment. Implement that.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41768 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 21 insertions, 6 deletions

diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index bb1fff5..9f7cb00 100644
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -182,7 +182,8 @@ void TargetData::init(const std::string &TargetDescription) {
   setAlignment(VECTOR_ALIGN,    8,  8, 64);  // v2i32
   setAlignment(VECTOR_ALIGN,   16, 16, 128); // v16i8, v8i16, v4i32, ...
   setAlignment(AGGREGATE_ALIGN, 0,  8,  0);  // struct, union, class, ...
-  
+  setAlignment(STACK_ALIGN,     0,  8,  0);  // objects on the stack
+
   while (!temp.empty()) {
     std::string token = getToken(temp, "-");
     std::string arg0 = getToken(token, ":");
@@ -204,10 +205,16 @@ void TargetData::init(const std::string &TargetDescription) {
     case 'i':
     case 'v':
     case 'f':
-    case 'a': {
-      AlignTypeEnum align_type = 
-        (*p == 'i' ? INTEGER_ALIGN : (*p == 'f' ? FLOAT_ALIGN :
-           (*p == 'v' ? VECTOR_ALIGN : AGGREGATE_ALIGN)));
+    case 'a':
+    case 's': {
+      AlignTypeEnum align_type;
+      switch(*p) {
+        case 'i': align_type = INTEGER_ALIGN; break;
+        case 'v': align_type = VECTOR_ALIGN; break;
+        case 'f': align_type = FLOAT_ALIGN; break;
+        case 'a': align_type = AGGREGATE_ALIGN; break;
+        case 's': align_type = STACK_ALIGN; break;
+      }
       uint32_t size = (uint32_t) atoi(++p);
       unsigned char abi_align = atoi(getToken(token, ":").c_str()) / 8;
       unsigned char pref_align = atoi(getToken(token, ":").c_str()) / 8;
@@ -529,6 +536,14 @@ unsigned char TargetData::getABITypeAlignment(const Type *Ty) const {
   return getAlignment(Ty, true);
 }
 
+unsigned char TargetData::getCallFrameTypeAlignment(const Type *Ty) const {
+  for (unsigned i = 0, e = Alignments.size(); i != e; ++i)
+    if (Alignments[i].AlignType == STACK_ALIGN)
+      return Alignments[i].ABIAlign;
+
+  return getABITypeAlignment(Ty);
+}
+
 unsigned char TargetData::getPrefTypeAlignment(const Type *Ty) const {
   return getAlignment(Ty, false);
 }
diff --git a/lib/Target/X86/X86Subtarget.h b/lib/Target/X86/X86Subtarget.h
index 493c801..d939bc0 100644
--- a/lib/Target/X86/X86Subtarget.h
+++ b/lib/Target/X86/X86Subtarget.h
@@ -146,7 +146,7 @@ public:
   std::string getDataLayout() const {
     const char *p;
     if (is64Bit())
-      p = "e-p:64:64-f64:64:64-i64:64:64-f80:128:128";
+      p = "e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128";
     else {
       if (isTargetDarwin())
         p = "e-p:32:32-f64:32:64-i64:32:64-f80:128:128";