Tested on x86_64-linux/darwin, OK for trunk?
(ideas for a more efficient discriminator welcome).
thanks
Iain
--- 8< ---
For Darwin versions up to darwin21, lazy symbol resolution requires use
of a stub that clobbers d10 and d11 on x86_64. However, this requirement
is overidden by the user specifying that a call is no_caller_saved_regs.
The current mechanism (querying an attribute) is a bit unfortunate on a
relatively hot path.
TODO: evaluate mechanisms for excluding the stub provision when the OS
target is new enough, and possible mechanisms for avoiding the attribute
lookup.
gcc/ChangeLog:
* config/i386/i386-expand.cc (ix86_expand_call): User setting of
no_caller_saved_registers overrides lazy symbol stub reservations.
Signed-off-by: Iain Sandoe <[email protected]>
---
gcc/config/i386/i386-expand.cc | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 19bc596983d..6cdcfc3f5f9 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -11520,15 +11520,18 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx
callarg1,
}
if (TARGET_MACHO && TARGET_64BIT && !sibcall
- && ((SYMBOL_REF_P (addr) && !SYMBOL_REF_LOCAL_P (addr))
- || !fndecl || TREE_PUBLIC (fndecl)))
+ && (!fndecl || TREE_PUBLIC (fndecl)
+ || (SYMBOL_REF_P (addr) && !SYMBOL_REF_LOCAL_P (addr)))
+ && (!fndecl || !lookup_attribute ("no_caller_saved_registers",
+ TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))))
{
/* We allow public functions defined in a TU to bind locally for PIC
code (the default) on 64bit Mach-O.
If such functions are not inlined, we cannot tell at compile-time if
they will be called via the lazy symbol resolver (this can depend on
options given at link-time). Therefore, we must assume that the lazy
- resolver could be used which clobbers R11 and R10. */
+ resolver could be used which clobbers R11 and R10.
+ User specification of "no caller saved regs" overides. */
clobber_reg (&use, gen_rtx_REG (DImode, R11_REG));
clobber_reg (&use, gen_rtx_REG (DImode, R10_REG));
}
--
2.50.1 (Apple Git-155)
