Remove the 's' DataLayout specification

During the years there have been some attempts at figuring out how to
align byval arguments. A look at the commit log suggests that they
were

* Use the ABI alignment.
* When that was not sufficient for x86-64, I added the 's' specification to
  DataLayout.
* When that was not sufficient Evan added the virtual getByValTypeAlignment.
* When even that was not sufficient, we just got the FE to add the alignment
  to the byval.

This patch is just a simple cleanup that removes my first attempt at fixing the
problem. I also added an AArch64 implementation of getByValTypeAlignment to
make sure this patch is a nop. I also left the 's' parsing for backward
compatibility.

I will send a short email to llvmdev about the change for anyone maintaining
an out of tree target.

llvm-svn: 198287

1 files changed, 5 insertions, 11 deletions

diff --git a/llvm/lib/IR/DataLayout.cpp b/llvm/lib/IR/DataLayout.cpp
index a22588628f7..0b52f1e95f3 100644
--- a/llvm/lib/IR/DataLayout.cpp
+++ b/llvm/lib/IR/DataLayout.cpp
@@ -225,6 +225,10 @@ void DataLayout::parseSpecifier(StringRef Desc) {
     Tok = Tok.substr(1);
 
     switch (Specifier) {
+    case 's':
+      // Ignored for backward compatibility.
+      // FIXME: remove this on LLVM 4.0.
+      break;
     case 'E':
       LittleEndian = false;
       break;
@@ -259,8 +263,7 @@ void DataLayout::parseSpecifier(StringRef Desc) {
     case 'i':
     case 'v':
     case 'f':
-    case 'a':
-    case 's': {
+    case 'a': {
       AlignTypeEnum AlignType;
       switch (Specifier) {
       default:
@@ -268,7 +271,6 @@ void DataLayout::parseSpecifier(StringRef Desc) {
       case 'v': AlignType = VECTOR_ALIGN; break;
       case 'f': AlignType = FLOAT_ALIGN; break;
       case 'a': AlignType = AGGREGATE_ALIGN; break;
-      case 's': AlignType = STACK_ALIGN; break;
       }
 
       // Bit size.
@@ -617,14 +619,6 @@ unsigned DataLayout::getABIIntegerTypeAlignment(unsigned BitWidth) const {
   return getAlignmentInfo(INTEGER_ALIGN, BitWidth, true, 0);
 }
 
-unsigned DataLayout::getCallFrameTypeAlignment(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 DataLayout::getPrefTypeAlignment(Type *Ty) const {
   return getAlignment(Ty, false);
 }