[PATCH] Use call-clobbered register for sibcall via GOT

[PATCH] Use call-clobbered register for sibcall via GOT

From: H.J. Lu  <hongjiu.lu@intel.com>

Since sibcall never returns, we can only use call-clobbered register as
GOT base.  Otherwise, callee-saved register used as GOT base won't be
properly restored.  sibcall_memory_operand is changed to allow 32-bit
GOT slot only with pseudo register as GOT base for RTL expansion.  2
new patterns, *sibcall_GOT_32 and *sibcall_value_GOT_32, are added to
expose GOT base register to register allocator so that call-clobbered
register will be used for GOT base.

gcc/

	PR target/68937
	* config/i386/i386.c (ix86_function_ok_for_sibcall): Count
	call to global function via GOT slot as indirect call.
	* config/i386/i386.md (*sibcall_GOT_32): New pattern.
	(*sibcall_value_GOT_32): Likewise.
	* config/i386/predicates.md (sibcall_memory_operand): Rewrite.
	Allow 32-bit GOT slot only with pseudo register as GOT base.
	(GOT32_symbol_operand): New predicate.

gcc/testsuite/

	PR target/68937
	* gcc.target/i386/pr68937-1.c: New test.
	* gcc.target/i386/pr68937-2.c: Likewise.
	* gcc.target/i386/pr68937-3.c: Likewise.
	* gcc.target/i386/pr68937-4.c: Likewise.
	* gcc.target/i386/pr68937-5.c: Likewise.
	* gcc.target/i386/pr68937-6.c: Likewise.

From-SVN: r231903