Simplify X86CompilationCallback: always align to 16-byte boundary; don't save EAX/EDX if unnecessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28910 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index f0b6499..af9466d 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -370,4 +370,20 @@
};
}
+// FASTCC_NUM_INT_ARGS_INREGS - This is the max number of integer arguments
+// to pass in registers. 0 is none, 1 is is "use EAX", 2 is "use EAX and
+// EDX". Anything more is illegal.
+//
+// FIXME: The linscan register allocator currently has problem with
+// coalescing. At the time of this writing, whenever it decides to coalesce
+// a physreg with a virtreg, this increases the size of the physreg's live
+// range, and the live range cannot ever be reduced. This causes problems if
+// too many physregs are coaleced with virtregs, which can cause the register
+// allocator to wedge itself.
+//
+// This code triggers this problem more often if we pass args in registers,
+// so disable it until this is fixed.
+//
+#define FASTCC_NUM_INT_ARGS_INREGS 0
+
#endif // X86ISELLOWERING_H