diff options
Diffstat (limited to 'gcc/config/i386/i386.c')
| -rw-r--r-- | gcc/config/i386/i386.c | 55 |
1 files changed, 50 insertions, 5 deletions
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 3ff5abb..cfdcb2f 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -1049,6 +1049,10 @@ int x86_prefetch_sse; /* ix86_regparm_string as a number */ static int ix86_regparm; +/* -mstackrealign option */ +extern int ix86_force_align_arg_pointer; +static const char ix86_force_align_arg_pointer_string[] = "force_align_arg_pointer"; + /* Preferred alignment for stack boundary in bits. */ unsigned int ix86_preferred_stack_boundary; @@ -2225,6 +2229,9 @@ const struct attribute_spec ix86_attribute_table[] = /* Sseregparm attribute says we are using x86_64 calling conventions for FP arguments. */ { "sseregparm", 0, 0, false, true, true, ix86_handle_cconv_attribute }, + /* force_align_arg_pointer says this function realigns the stack at entry. */ + { (const char *)&ix86_force_align_arg_pointer_string, 0, 0, + false, true, true, ix86_handle_cconv_attribute }, #if TARGET_DLLIMPORT_DECL_ATTRIBUTES { "dllimport", 0, 0, false, false, false, handle_dll_attribute }, { "dllexport", 0, 0, false, false, false, handle_dll_attribute }, @@ -2367,6 +2374,15 @@ ix86_handle_cconv_attribute (tree *node, tree name, *no_add_attrs = true; } + if (!TARGET_64BIT + && lookup_attribute (ix86_force_align_arg_pointer_string, + TYPE_ATTRIBUTES (*node)) + && compare_tree_int (cst, REGPARM_MAX-1)) + { + error ("%s functions limited to %d register parameters", + ix86_force_align_arg_pointer_string, REGPARM_MAX-1); + } + return NULL_TREE; } @@ -2506,6 +2522,18 @@ ix86_function_regparm (tree type, tree decl) && decl_function_context (decl) && !DECL_NO_STATIC_CHAIN (decl)) local_regparm = 2; + /* If the function realigns its stackpointer, the + prologue will clobber %ecx. If we've already + generated code for the callee, the callee + DECL_STRUCT_FUNCTION is gone, so we fall back to + scanning the attributes for the self-realigning + property. */ + if ((DECL_STRUCT_FUNCTION (decl) + && DECL_STRUCT_FUNCTION (decl)->machine->force_align_arg_pointer) + || (!DECL_STRUCT_FUNCTION (decl) + && lookup_attribute (ix86_force_align_arg_pointer_string, + TYPE_ATTRIBUTES (TREE_TYPE (decl))))) + local_regparm = 2; /* Each global register variable increases register preassure, so the more global reg vars there are, the smaller regparm optimization use, unless requested by the user explicitly. */ @@ -5181,11 +5209,28 @@ pro_epilogue_adjust_stack (rtx dest, rtx src, rtx offset, int style) static rtx ix86_internal_arg_pointer (void) { - if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN - && DECL_NAME (current_function_decl) - && MAIN_NAME_P (DECL_NAME (current_function_decl)) - && DECL_FILE_SCOPE_P (current_function_decl)) - { + bool has_force_align_arg_pointer = + (0 != lookup_attribute (ix86_force_align_arg_pointer_string, + TYPE_ATTRIBUTES (TREE_TYPE (current_function_decl)))); + if ((FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN + && DECL_NAME (current_function_decl) + && MAIN_NAME_P (DECL_NAME (current_function_decl)) + && DECL_FILE_SCOPE_P (current_function_decl)) + || ix86_force_align_arg_pointer + || has_force_align_arg_pointer) + { + /* Nested functions can't realign the stack due to a register + conflict. */ + if (DECL_CONTEXT (current_function_decl) + && TREE_CODE (DECL_CONTEXT (current_function_decl)) == FUNCTION_DECL) + { + if (ix86_force_align_arg_pointer) + warning (0, "-mstackrealign ignored for nested functions"); + if (has_force_align_arg_pointer) + error ("%s not supported for nested functions", + ix86_force_align_arg_pointer_string); + return virtual_incoming_args_rtx; + } cfun->machine->force_align_arg_pointer = gen_rtx_REG (Pmode, 2); return copy_to_reg (cfun->machine->force_align_arg_pointer); } |