On December 23, 2016 6:47:37 PM GMT+01:00, Richard Sandiford
<[email protected]> wrote:
>virtual_operand_p handled SSA names by looking at the flags of the
>underlying variable. This seems to be a relatively common source
>of cache misses, mainly because virtual_operand_p is the first thing
>tested by is_gimple_reg.
>
>This patch caches the information in the SSA name itself. Several
>flags seem to be free so the patch arbitrarily uses public_flag.
>
>Tested on aarch64-linux-gnu and x86_64-linux-gnu. It improves
>compile time by a small (<1%) but reproducable amount on the
>tests I've tried. OK to install?
OK.
Richard.
>Thanks,
>Richard
>
>
>gcc/
> * tree-core.h (tree_base): Document the meaning of public_flag
> for SSA names.
> * tree.h (SSA_NAME_IS_VIRTUAL_OPERAND): New macro.
> (SET_SSA_NAME_VAR_OR_IDENTIFIER): Record whether the variable
> is a virtual operand.
> * gimple-expr.h (virtual_operand_p): Use SSA_NAME_IS_VIRTUAL_OPERAND.
>
>diff --git a/gcc/gimple-expr.h b/gcc/gimple-expr.h
>index f2ccd29..faf4c53 100644
>--- a/gcc/gimple-expr.h
>+++ b/gcc/gimple-expr.h
>@@ -105,11 +105,7 @@ static inline bool
> virtual_operand_p (tree op)
> {
> if (TREE_CODE (op) == SSA_NAME)
>- {
>- op = SSA_NAME_VAR (op);
>- if (!op)
>- return false;
>- }
>+ return SSA_NAME_IS_VIRTUAL_OPERAND (op);
>
> if (TREE_CODE (op) == VAR_DECL)
> return VAR_DECL_IS_VIRTUAL_OPERAND (op);
>diff --git a/gcc/tree-core.h b/gcc/tree-core.h
>index eec2d4f3..59d771c 100644
>--- a/gcc/tree-core.h
>+++ b/gcc/tree-core.h
>@@ -1091,6 +1091,9 @@ struct GTY(()) tree_base {
> FALLTHROUGH_LABEL_P in
> LABEL_DECL
>
>+ SSA_NAME_IS_VIRTUAL_OPERAND in
>+ SSA_NAME
>+
> private_flag:
>
> TREE_PRIVATE in
>diff --git a/gcc/tree.h b/gcc/tree.h
>index 62cd7bb..e994e93 100644
>--- a/gcc/tree.h
>+++ b/gcc/tree.h
>@@ -1665,6 +1665,11 @@ extern void protected_set_expr_location (tree,
>location_t);
>
> /* SSA_NAME accessors. */
>
>+/* Whether SSA_NAME NODE is a virtual operand. This simply caches the
>+ information in the underlying SSA_NAME_VAR for efficiency. */
>+#define SSA_NAME_IS_VIRTUAL_OPERAND(NODE) \
>+ SSA_NAME_CHECK (NODE)->base.public_flag
>+
> /* Returns the IDENTIFIER_NODE giving the SSA name a name or NULL_TREE
> if there is no name associated with it. */
> #define SSA_NAME_IDENTIFIER(NODE) \
>@@ -1683,7 +1688,16 @@ extern void protected_set_expr_location (tree,
>location_t);
> ? NULL_TREE : (NODE)->ssa_name.var)
>
> #define SET_SSA_NAME_VAR_OR_IDENTIFIER(NODE,VAR) \
>- do { SSA_NAME_CHECK (NODE)->ssa_name.var = (VAR); } while (0)
>+ do \
>+ { \
>+ tree var_ = (VAR); \
>+ SSA_NAME_CHECK (NODE)->ssa_name.var = var_; \
>+ SSA_NAME_IS_VIRTUAL_OPERAND (NODE) \
>+ = (var_ \
>+ && TREE_CODE (var_) == VAR_DECL \
>+ && VAR_DECL_IS_VIRTUAL_OPERAND (var_)); \
>+ } \
>+ while (0)
>
> /* Returns the statement which defines this SSA name. */
>#define SSA_NAME_DEF_STMT(NODE) SSA_NAME_CHECK
>(NODE)->ssa_name.def_stmt
