put zero initialized entities into bss section (not just uninitialized ones); TLS...

[r27108]

diff --git a/ir/be/begnuas.c b/ir/be/begnuas.c
index 0136046..b963558 100644 (file)
--- a/ir/be/begnuas.c
+++ b/ir/be/begnuas.c
@@ -67,6 +67,7 @@ static const char *get_section_name(be_gas_section_t section)
                        ".section\t.data",
                        ".section\t.rodata",
                        ".section\t.bss",
+                       ".section\t.tdata,\"awT\",@progbits",
                        ".section\t.tbss,\"awT\",@nobits",
                        ".section\t.ctors,\"aw\",@progbits",
                        ".section\t.dtors,\"aw\",@progbits",
@@ -79,6 +80,7 @@ static const char *get_section_name(be_gas_section_t section)
                        ".section\t.data",
                        ".section .rdata,\"dr\"",
                        ".section\t.bss",
+                       ".section\t.tdata,\"awT\",@progbits",
                        ".section\t.tbss,\"awT\",@nobits",
                        ".section\t.ctors,\"w\"",
                        ".section\t.dtors,\"w\"",
@@ -92,6 +94,7 @@ static const char *get_section_name(be_gas_section_t section)
                        ".const",
                        ".data",
                        NULL,             /* TLS is not supported on Mach-O */
+                       NULL,             /* TLS is not supported on Mach-O */
                        ".mod_init_func",
                        ".mod_term_func",
                        ".cstring",
@@ -623,6 +626,47 @@ static int ent_is_string_const(const ir_entity *ent)
        return 0;
 }
 
+static bool initializer_is_null(const ir_initializer_t *initializer)
+{
+       switch (initializer->kind) {
+       case IR_INITIALIZER_NULL:
+               return true;
+       case IR_INITIALIZER_TARVAL: {
+               tarval *tv = initializer->tarval.value;
+               return tarval_is_null(tv);
+       }
+       case IR_INITIALIZER_CONST: {
+               ir_node *value = initializer->consti.value;
+               if (!is_Const(value))
+                       return false;
+               return is_Const_null(value);
+       }
+       case IR_INITIALIZER_COMPOUND: {
+               size_t i;
+               for (i = 0; i < initializer->compound.n_initializers; ++i) {
+                       ir_initializer_t *subinitializer
+                               = initializer->compound.initializers[i];
+                       if (!initializer_is_null(subinitializer))
+                               return false;
+               }
+               return true;
+       }
+       }
+       panic("invalid initializer in initializer_is_null");
+}
+
+static bool entity_is_null(const ir_entity *entity)
+{
+       if (entity->initializer != NULL) {
+               return initializer_is_null(entity->initializer);
+       } else if (entity_has_compound_ent_values(entity)) {
+               /* I'm too lazy to implement this case as compound graph paths will be
+                * remove anyway in the future */
+       }
+       /* uninitialized, NULL is fine */
+       return true;
+}
+
 /**
  * Dump a string constant.
  * No checks are made!!
@@ -675,7 +719,7 @@ static void dump_string_cst(const ir_entity *ent)
        remaining_space = type_size - len;
        assert(remaining_space >= 0);
        if (remaining_space > 0) {
-               be_emit_irprintf("\t.space\t%d\n", remaining_space);
+               be_emit_irprintf("\t.zero\t%d\n", remaining_space);
        }
 }
 
@@ -1135,6 +1179,9 @@ static be_gas_section_t determine_section(be_gas_decl_env_t *env,
        ir_type *owner = get_entity_owner(entity);
 
        if (owner == get_segment_type(IR_SEGMENT_GLOBAL)) {
+               if (is_method_entity(entity))
+                       return GAS_SECTION_TEXT;
+
                ir_linkage linkage = get_entity_linkage(entity);
                if (linkage & IR_LINKAGE_CONSTANT) {
                        /* mach-o is the only one with a cstring section */
@@ -1144,11 +1191,10 @@ static be_gas_section_t determine_section(be_gas_decl_env_t *env,
 
                        return GAS_SECTION_RODATA;
                }
-               if (!entity_has_definition(entity))
+               if (entity_is_null(entity))
                        return GAS_SECTION_BSS;
 
                return GAS_SECTION_DATA;
-
        } else if (owner == env->main_env->pic_symbols_type) {
                return GAS_SECTION_PIC_SYMBOLS;
        } else if (owner == env->main_env->pic_trampolines_type) {
@@ -1158,7 +1204,15 @@ static be_gas_section_t determine_section(be_gas_decl_env_t *env,
        } else if (owner == get_segment_type(IR_SEGMENT_DESTRUCTORS)) {
                return GAS_SECTION_DESTRUCTORS;
        } else if (owner == get_segment_type(IR_SEGMENT_THREAD_LOCAL)) {
-               return GAS_SECTION_TLS;
+               ir_linkage linkage = get_entity_linkage(entity);
+               if (linkage & IR_LINKAGE_MERGE) {
+                       panic("IR_LINKAGE_MERGE not supported for THREAD_LOCAL entities");
+               }
+
+               if (entity_is_null(entity)) {
+                       return GAS_SECTION_TLS_BSS;
+               }
+               return GAS_SECTION_TLS_DATA;
        }
 
        panic("Couldn't determine section for %+F?!?", entity);
@@ -1280,14 +1334,14 @@ static void dump_global(be_gas_decl_env_t *env, const ir_entity *ent)
                be_emit_write_line();
        }
 
-       if (ent->initializer != NULL) {
-               dump_initializer(env, ent);
+       if (section == GAS_SECTION_BSS || section == GAS_SECTION_TLS_BSS) {
+               be_emit_irprintf("\t.zero %u\n", get_type_size_bytes(type));
+               be_emit_write_line();
        } else if(entity_has_compound_ent_values(ent)) {
                dump_compound_graph_init(env, ent);
        } else {
-               /* uninitialized */
-               be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
-               be_emit_write_line();
+               assert(ent->initializer != NULL);
+               dump_initializer(env, ent);
        }
 }