[aot] Use nops as alignment padding on amd64 instead of zeros.

diff --git a/mono/mini/aot-compiler.c b/mono/mini/aot-compiler.c
index deaac7afec024e171c19ade086218cb322b05b53..8b6ac8360431b6c8eb64a858023c60e97cb2a5bb 100644 (file)
--- a/mono/mini/aot-compiler.c
+++ b/mono/mini/aot-compiler.c
@@ -206,6 +206,7 @@ typedef struct MonoAotCompile {
        const char *user_symbol_prefix;
        const char *llvm_label_prefix;
        const char *inst_directive;
+       int align_pad_value;
        guint32 label_generator;
        gboolean llvm;
        MonoAotFileFlags flags;
@@ -366,9 +367,39 @@ emit_line (MonoAotCompile *acfg)
 }
 
 static inline void
-emit_alignment (MonoAotCompile *acfg, int size) 
+emit_alignment (MonoAotCompile *acfg, int size)
 { 
-       img_writer_emit_alignment (acfg->w, size); 
+       img_writer_emit_alignment (acfg->w, size);
+}
+
+static inline void
+emit_alignment_code (MonoAotCompile *acfg, int size)
+{
+       if (acfg->align_pad_value)
+               img_writer_emit_alignment_fill (acfg->w, size, acfg->align_pad_value);
+       else
+               img_writer_emit_alignment (acfg->w, size);
+}
+
+static inline void
+emit_padding (MonoAotCompile *acfg, int size)
+{
+       int i;
+       guint8 buf [16];
+
+       if (acfg->align_pad_value) {
+               for (i = 0; i < 16; ++i)
+                       buf [i] = acfg->align_pad_value;
+       } else {
+               memset (buf, 0, sizeof (buf));
+       }
+
+       for (i = 0; i < size; i += 16) {
+               if (size - i < 16)
+                       emit_bytes (acfg, buf, size - i);
+               else
+                       emit_bytes (acfg, buf, 16);
+       }
 }
 
 static inline void
@@ -685,6 +716,8 @@ arch_init (MonoAotCompile *acfg)
 
 #if defined(TARGET_AMD64)
        g_string_append (acfg->llc_args, " -march=x86-64 -mattr=sse4.1");
+       /* NOP */
+       acfg->align_pad_value = 0x90;
 #endif
 
 #ifdef TARGET_ARM
@@ -4920,10 +4953,9 @@ emit_method_code (MonoAotCompile *acfg, MonoCompile *cfg)
        method_index = get_method_index (acfg, method);
        symbol = g_strdup_printf ("%sme_%x", acfg->temp_prefix, method_index);
 
-
        /* Make the labels local */
        emit_section_change (acfg, ".text", 0);
-       emit_alignment (acfg, func_alignment);
+       emit_alignment_code (acfg, func_alignment);
        
        if (acfg->global_symbols && acfg->need_no_dead_strip)
                fprintf (acfg->fp, "    .no_dead_strip %s\n", cfg->asm_symbol);
@@ -5734,7 +5766,7 @@ emit_plt (MonoAotCompile *acfg)
        sprintf (symbol, "plt");
 
        emit_section_change (acfg, ".text", 0);
-       emit_alignment (acfg, NACL_SIZE(16, kNaClAlignment));
+       emit_alignment_code (acfg, NACL_SIZE(16, kNaClAlignment));
        emit_label (acfg, symbol);
        emit_label (acfg, acfg->plt_symbol);
 
@@ -5877,7 +5909,7 @@ emit_trampoline_full (MonoAotCompile *acfg, int got_offset, MonoTrampInfo *info,
 
        emit_section_change (acfg, ".text", 0);
        emit_global (acfg, start_symbol, TRUE);
-       emit_alignment (acfg, AOT_FUNC_ALIGNMENT);
+       emit_alignment_code (acfg, AOT_FUNC_ALIGNMENT);
        emit_label (acfg, start_symbol);
 
        sprintf (symbol, "%snamed_%s", acfg->temp_prefix, name);
@@ -6135,7 +6167,7 @@ emit_trampolines (MonoAotCompile *acfg)
                        if (acfg->aot_opts.write_symbols)
                                emit_local_symbol (acfg, symbol, end_symbol, TRUE);
 
-                       emit_alignment (acfg, AOT_FUNC_ALIGNMENT);
+                       emit_alignment_code (acfg, AOT_FUNC_ALIGNMENT);
                        emit_label (acfg, symbol);
 
                        acfg->trampoline_got_offset_base [ntype] = tramp_got_offset;
@@ -7175,7 +7207,7 @@ emit_code (MonoAotCompile *acfg)
         * AOT code, so it must be equal to the address of the first emitted method.
         */
        emit_section_change (acfg, ".text", 0);
-       emit_alignment (acfg, 8);
+       emit_alignment_code (acfg, 8);
        if (acfg->llvm) {
                for (i = 0; i < acfg->nmethods; ++i) {
                        if (acfg->cfgs [i] && acfg->cfgs [i]->compile_llvm) {
@@ -7195,7 +7227,7 @@ emit_code (MonoAotCompile *acfg)
         * same address as 'methods'.
         */
 #if defined(__default_codegen__)
-       emit_zero_bytes (acfg, 16);
+       emit_padding (acfg, 16);
 #elif defined(__native_client_codegen__)
        {
                const int kPaddingSize = 16;
@@ -7236,9 +7268,8 @@ emit_code (MonoAotCompile *acfg)
 
                        arch_emit_unbox_trampoline (acfg, cfg, cfg->orig_method, cfg->asm_symbol);
 
-                       if (acfg->thumb_mixed && cfg->compile_llvm) {
+                       if (acfg->thumb_mixed && cfg->compile_llvm)
                                emit_set_arm_mode (acfg);
-                       }
                }
 
                if (cfg->compile_llvm)
@@ -7249,10 +7280,10 @@ emit_code (MonoAotCompile *acfg)
 
        sprintf (symbol, "methods_end");
        emit_section_change (acfg, ".text", 0);
-       emit_alignment (acfg, 8);
+       emit_alignment_code (acfg, 8);
        emit_label (acfg, symbol);
        /* To distinguish it from the next symbol */
-       emit_int32 (acfg, 0);
+       emit_padding (acfg, 4);
 
        /* 
         * Add .no_dead_strip directives for all LLVM methods to prevent the OSX linker
@@ -7278,7 +7309,7 @@ emit_code (MonoAotCompile *acfg)
                 */
                sprintf (symbol, "method_addresses");
                emit_section_change (acfg, ".text", 1);
-               emit_alignment (acfg, 8);
+               emit_alignment_code (acfg, 8);
                emit_label (acfg, symbol);
                emit_local_symbol (acfg, symbol, "method_addresses_end", TRUE);
                emit_unset_mode (acfg);
@@ -7329,7 +7360,7 @@ emit_code (MonoAotCompile *acfg)
                emit_section_change (acfg, ".text", 0);
        else
                emit_section_change (acfg, RODATA_SECT, 0);
-       emit_alignment (acfg, 8);
+       emit_alignment_code (acfg, 8);
        emit_label (acfg, symbol);
 
        prev_index = -1;
@@ -8144,7 +8175,7 @@ emit_mem_end (MonoAotCompile *acfg)
 
        sprintf (symbol, "mem_end");
        emit_section_change (acfg, ".text", 1);
-       emit_alignment (acfg, 8);
+       emit_alignment_code (acfg, 8);
        emit_label (acfg, symbol);
 }
 
@@ -9084,7 +9115,7 @@ mono_compile_assembly (MonoAssembly *ass, guint32 opts, const char *aot_options)
                 */
                sprintf (symbol, "thumb_end");
                emit_section_change (acfg, ".text", 0);
-               emit_alignment (acfg, 8);
+               emit_alignment_code (acfg, 8);
                emit_label (acfg, symbol);
                emit_zero_bytes (acfg, 16);
 

diff --git a/mono/mini/image-writer.c b/mono/mini/image-writer.c
index 13c055bd1e1ba03d072608f561c395b7bfae19be..acf392b440f7dfbb434a82c8ea79a71237af6283 100644 (file)
--- a/mono/mini/image-writer.c
+++ b/mono/mini/image-writer.c
@@ -1843,6 +1843,17 @@ asm_writer_emit_alignment (MonoImageWriter *acfg, int size)
 #endif
 }
 
+static void 
+asm_writer_emit_alignment_fill (MonoImageWriter *acfg, int size, int fill)
+{
+       asm_writer_emit_unset_mode (acfg);
+#if defined(TARGET_ASM_APPLE)
+       fprintf (acfg->fp, "\t.align %d, 0x%0x\n", ilog2 (size), fill);
+#else
+       asm_writer_emit_alignment (acfg, size);
+#endif
+}
+
 #ifdef __native_client_codegen__
 static void
 asm_writer_emit_nacl_call_alignment (MonoImageWriter *acfg) {
@@ -2150,6 +2161,19 @@ img_writer_emit_alignment (MonoImageWriter *acfg, int size)
 #endif
 }
 
+void
+img_writer_emit_alignment_fill (MonoImageWriter *acfg, int size, int fill)
+{
+#ifdef USE_BIN_WRITER
+       if (acfg->use_bin_writer)
+               bin_writer_emit_alignment (acfg, size);
+       else
+               asm_writer_emit_alignment (acfg, size);
+#else
+       asm_writer_emit_alignment_fill (acfg, size, fill);
+#endif
+}
+
 #ifdef __native_client_codegen__
 void
 img_writer_emit_nacl_call_alignment (MonoImageWriter *acfg) {

diff --git a/mono/mini/image-writer.h b/mono/mini/image-writer.h
index 720b95f97ada9c3572ac91578d350d7978234989..812c15462d2ada5a388cb9be90f3154964a09b00 100644 (file)
--- a/mono/mini/image-writer.h
+++ b/mono/mini/image-writer.h
@@ -62,6 +62,8 @@ void img_writer_emit_line (MonoImageWriter *w) MONO_INTERNAL;
 
 void img_writer_emit_alignment (MonoImageWriter *w, int size) MONO_INTERNAL;
 
+void img_writer_emit_alignment_fill (MonoImageWriter *w, int size, int fill) MONO_INTERNAL;
+
 #ifdef __native_client_codegen__
 void img_writer_emit_nacl_call_alignment (MonoImageWriter *w) MONO_INTERNAL;
 #endif