* doc/tm.texi (TARGET_MD_ASM_CLOBBERS): Adjust wording to not

	imply that this is called once, independent of asms in code.
	Adjust to now being pased output and input lists.  Mention helper
	function decl_overlaps_hard_reg_set_p.
	* hooks.c (hook_tree_tree_tree_tree_3rd_identity): Rename from
	hook_tree_tree_identity and to take three trees, returning third.
	* hooks.h (hook_tree_tree_tree_tree_3rd_identity): Adjust the
	prototype.
	* stmt.c: include hard-reg-set.h before tree.h.
	(decl_overlaps_hard_reg_set_p): New function, broken out from...
	(decl_conflicts_with_clobbers_p): Call
	decl_overlaps_hard_reg_set_p.
	(expand_asm_operands): Pass output and input lists in call to
	targetm.md_asm_clobbers.
	* target-def.h (TARGET_MD_ASM_CLOBBERS): Define as
	hook_tree_tree_tree_tree_3rd_identity.
	* target.h (struct gcc_target.md_asm_clobbers): Take three tree
	parameters.
	* tree.h [HARD_CONST] (decl_overlaps_hard_reg_set_p): Prototype.
	* config/i386/i386.c (ix86_md_asm_clobbers): Adjust to three
	parameters, first two unused.
	* config/cris/cris.c (cris_md_asm_clobbers): Adjust to added
	parameters.  Only add MOF to clobbers if there's no 'h' mentioned
	in constraint letters and MOF is not mentioned as a asm-declared
	register in neither of the input and output lists.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@96923 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 7 insertions, 3 deletions

diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 799a0f854d3..af269f2a97c 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -9314,11 +9314,15 @@ from shared libraries (DLLs).
 You need not define this macro if it would always evaluate to zero.
 @end defmac
 
-@deftypefn {Target Hook} tree TARGET_MD_ASM_CLOBBERS (tree @var{clobbers})
+@deftypefn {Target Hook} tree TARGET_MD_ASM_CLOBBERS (tree @var{outputs}, tree @var{inputs}, tree @var{clobbers})
 This target hook should add to @var{clobbers} @code{STRING_CST} trees for
-any hard regs the port wishes to automatically clobber for all asms.
+any hard regs the port wishes to automatically clobber for an asm.
 It should return the result of the last @code{tree_cons} used to add a
-clobber.
+clobber.  The @var{outputs}, @var{inputs} and @var{clobber} lists are the
+corresponding parameters to the asm and may be inspected to avoid
+clobbering a register that is an input or output of the asm.  You can use
+@code{decl_overlaps_hard_reg_set_p}, declared in @file{tree.h}, to test
+for overlap with regards to asm-declared registers.
 @end deftypefn
 
 @defmac MATH_LIBRARY