6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-08-23 17:29:19 +00:00
Code Issues Projects Releases Wiki Activity

Allow targets to specify a minimum supported NOP size when performing NOP padding. If the desired padding is smaller than the supported NOP size,

Browse Source 
we will enlarge the padding to make it work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162870 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2012-08-29 22:18:56 +00:00
parent 66390805ad
commit 15b7a98ece
2 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
include/llvm/MC/MCAsmBackend.h
View File

@ -133,6 +133,13 @@ public:
/// @}
/// getMinimumNopSize - Returns the minimum size of a nop in bytes on this
/// target. The assembler will use this to emit excess padding in situations
/// where the padding required for simple alignment would be less than the
/// minimum nop size.
///
virtual unsigned getMinimumNopSize() const { return 1; }
/// writeNopData - Write an (optimal) nop sequence of Count bytes to the given
/// output. If the target cannot generate such a sequence, it should return an
/// error.

6
lib/MC/MCAssembler.cpp
View File

@ -325,6 +325,12 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
const MCAlignFragment &AF = cast<MCAlignFragment>(F);
unsigned Offset = Layout.getFragmentOffset(&AF);
unsigned Size = OffsetToAlignment(Offset, AF.getAlignment());
// If we are padding with nops, force the padding to be larger than the
// minimum nop size.
if (Size > 0 && AF.hasEmitNops()) {
while (Size % getBackend().getMinimumNopSize())
Size += AF.getAlignment();
}
if (Size > AF.getMaxBytesToEmit())
return 0;
return Size;