changeset b3585da1f970 in /z/repo/gem5
details: http://repo.gem5.org/gem5?cmd=changeset;node=b3585da1f970
description:
X86: Make sure instruction flags are set properly even on 32 bit
machines.
The way flag bits were being set for microops in x86 ended up implicitly
calling the bitset constructor which was truncating flags beyond the
width of
an unsigned long. This change sets the bits in chunks which are always
small
enough to avoid being truncated. On 64 bit machines this should reduce
to be
the same as before, and on 32 bit machines it should work properly and
not be
unreasonably inefficient.
diffstat:
src/arch/x86/insts/microop.hh | 10 +++++++++-
1 files changed, 9 insertions(+), 1 deletions(-)
diffs (20 lines):
diff -r d04ae08781e2 -r b3585da1f970 src/arch/x86/insts/microop.hh
--- a/src/arch/x86/insts/microop.hh Mon Sep 05 02:48:57 2011 -0700
+++ b/src/arch/x86/insts/microop.hh Mon Sep 05 18:36:26 2011 -0700
@@ -100,7 +100,15 @@
X86ISA::X86StaticInst(mnem, _machInst, __opClass),
instMnem(_instMnem)
{
- flags |= setFlags;
+ const int ChunkSize = sizeof(unsigned long);
+ const int Chunks = sizeof(setFlags) / ChunkSize;
+
+ // Since the bitset constructor can only handle unsigned long
+ // sized chunks, feed it those one at a time while oring them in.
+ for (int i = 0; i < Chunks; i++) {
+ unsigned shift = i * ChunkSize * 8;
+ flags |= (std::bitset<NumFlags>(setFlags >> shift) << shift);
+ }
}
std::string generateDisassembly(Addr pc,
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