asm inline

The Linux kernel people want a feature that makes GCC pretend some
inline assembler code is tiny (while it would think it is huge), so
that such code will be inlined essentially always instead of
essentially never.

This patch lets you say "asm inline" instead of just "asm", with the
result that that inline assembler is always counted as minimum cost
for inlining.  It implements this for C and C++, making "inline"
another asm-qualifier (supplementing "volatile" and "goto").


	* doc/extend.texi (Using Assembly Language with C): Document asm inline.
	(Size of an asm): Fix typo.  Document asm inline.
	* gimple-pretty-print.c (dump_gimple_asm): Handle asm inline.
	* gimple.h (enum gf_mask): Add GF_ASM_INLINE.
	(gimple_asm_set_volatile): Fix typo.
	(gimple_asm_inline_p): New.
	(gimple_asm_set_inline): New.
	* gimplify.c (gimplify_asm_expr): Propagate the asm inline flag from
	tree to gimple.
	* ipa-icf-gimple.c (func_checker::compare_gimple_asm): Compare the
	gimple_asm_inline_p flag, too.
	* tree-core.h (tree_base): Document that protected_flag is ASM_INLINE_P
	in an ASM_EXPR.
	* tree-inline.c (estimate_num_insns): If gimple_asm_inline_p return
	a minimum size for an asm.
	* tree.h (ASM_INLINE_P): New.

gcc/c/
	* c-parser.c (c_parser_asm_statement): Detect the inline keyword
	after asm.  Pass a flag for it to build_asm_expr.
	* c-tree.h (build_asm_expr): Update declaration.
	* c-typeck.c (build_asm_stmt): Add is_inline parameter.  Use it to
	set ASM_INLINE_P.

gcc/cp/
	* cp-tree.h (finish_asm_stmt): Update declaration.
	* parser.c (cp_parser_asm_definition): Detect the inline keyword
	after asm.  Pass a flag for it to finish_asm_stmt.
	* pt.c (tsubst_expr): Pass the ASM_INLINE_P flag to finish_asm_stmt.
	* semantics.c (finish_asm_stmt): Add inline_p parameter.  Use it to
	set ASM_INLINE_P.

gcc/testsuite/
	* c-c++-common/torture/asm-inline.c: New testcase.
	* gcc.dg/asm-qual-2.c: Test asm inline, too.

From-SVN: r266860

1 files changed, 24 insertions, 2 deletions

diff --git a/gcc/gimple.h b/gcc/gimple.h
index 9853521..37fd5fb 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -137,6 +137,7 @@ enum gimple_rhs_class
 enum gf_mask {
     GF_ASM_INPUT		= 1 << 0,
     GF_ASM_VOLATILE		= 1 << 1,
+    GF_ASM_INLINE		= 1 << 2,
     GF_CALL_FROM_THUNK		= 1 << 0,
     GF_CALL_RETURN_SLOT_OPT	= 1 << 1,
     GF_CALL_TAILCALL		= 1 << 2,
@@ -3911,7 +3912,7 @@ gimple_asm_string (const gasm *asm_stmt)
 }
 
 
-/* Return true ASM_STMT ASM_STMT is an asm statement marked volatile.  */
+/* Return true if ASM_STMT is marked volatile.  */
 
 static inline bool
 gimple_asm_volatile_p (const gasm *asm_stmt)
@@ -3920,7 +3921,7 @@ gimple_asm_volatile_p (const gasm *asm_stmt)
 }
 
 
-/* If VOLATLE_P is true, mark asm statement ASM_STMT as volatile.  */
+/* If VOLATILE_P is true, mark asm statement ASM_STMT as volatile.  */
 
 static inline void
 gimple_asm_set_volatile (gasm *asm_stmt, bool volatile_p)
@@ -3932,6 +3933,27 @@ gimple_asm_set_volatile (gasm *asm_stmt, bool volatile_p)
 }
 
 
+/* Return true if ASM_STMT is marked inline.  */
+
+static inline bool
+gimple_asm_inline_p (const gasm *asm_stmt)
+{
+  return (asm_stmt->subcode & GF_ASM_INLINE) != 0;
+}
+
+
+/* If INLINE_P is true, mark asm statement ASM_STMT as inline.  */
+
+static inline void
+gimple_asm_set_inline (gasm *asm_stmt, bool inline_p)
+{
+  if (inline_p)
+    asm_stmt->subcode |= GF_ASM_INLINE;
+  else
+    asm_stmt->subcode &= ~GF_ASM_INLINE;
+}
+
+
 /* If INPUT_P is true, mark asm ASM_STMT as an ASM_INPUT.  */
 
 static inline void