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authorMichael Rolnik <mrolnik@gmail.com>2020-01-24 01:51:15 +0100
committerPhilippe Mathieu-Daudé <f4bug@amsat.org>2020-07-11 11:02:05 +0200
commit9baade8d3be8506daa9962ce54d39e25b2b220f1 (patch)
treeabd592bdc4d40c553eb1c627fced466a34f962f7 /target
parent46188cabae4a13add28493f85b0f65ddde3ead41 (diff)
target/avr: Add instruction translation - CPU main translation function
Add the core of translation mechanism. Co-developed-by: Richard Henderson <richard.henderson@linaro.org> Co-developed-by: Michael Rolnik <mrolnik@gmail.com> Signed-off-by: Michael Rolnik <mrolnik@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com> Signed-off-by: Thomas Huth <huth@tuxfamily.org> Message-Id: <20200705140315.260514-17-huth@tuxfamily.org> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Diffstat (limited to 'target')
-rw-r--r--target/avr/translate.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/target/avr/translate.c b/target/avr/translate.c
index ee7811995a..7ad3dec031 100644
--- a/target/avr/translate.c
+++ b/target/avr/translate.c
@@ -2805,3 +2805,216 @@ static bool trans_WDR(DisasContext *ctx, arg_WDR *a)
return true;
}
+
+/*
+ * Core translation mechanism functions:
+ *
+ * - translate()
+ * - canonicalize_skip()
+ * - gen_intermediate_code()
+ * - restore_state_to_opc()
+ *
+ */
+static void translate(DisasContext *ctx)
+{
+ uint32_t opcode = next_word(ctx);
+
+ if (!decode_insn(ctx, opcode)) {
+ gen_helper_unsupported(cpu_env);
+ ctx->bstate = DISAS_NORETURN;
+ }
+}
+
+/* Standardize the cpu_skip condition to NE. */
+static bool canonicalize_skip(DisasContext *ctx)
+{
+ switch (ctx->skip_cond) {
+ case TCG_COND_NEVER:
+ /* Normal case: cpu_skip is known to be false. */
+ return false;
+
+ case TCG_COND_ALWAYS:
+ /*
+ * Breakpoint case: cpu_skip is known to be true, via TB_FLAGS_SKIP.
+ * The breakpoint is on the instruction being skipped, at the start
+ * of the TranslationBlock. No need to update.
+ */
+ return false;
+
+ case TCG_COND_NE:
+ if (ctx->skip_var1 == NULL) {
+ tcg_gen_mov_tl(cpu_skip, ctx->skip_var0);
+ } else {
+ tcg_gen_xor_tl(cpu_skip, ctx->skip_var0, ctx->skip_var1);
+ ctx->skip_var1 = NULL;
+ }
+ break;
+
+ default:
+ /* Convert to a NE condition vs 0. */
+ if (ctx->skip_var1 == NULL) {
+ tcg_gen_setcondi_tl(ctx->skip_cond, cpu_skip, ctx->skip_var0, 0);
+ } else {
+ tcg_gen_setcond_tl(ctx->skip_cond, cpu_skip,
+ ctx->skip_var0, ctx->skip_var1);
+ ctx->skip_var1 = NULL;
+ }
+ ctx->skip_cond = TCG_COND_NE;
+ break;
+ }
+ if (ctx->free_skip_var0) {
+ tcg_temp_free(ctx->skip_var0);
+ ctx->free_skip_var0 = false;
+ }
+ ctx->skip_var0 = cpu_skip;
+ return true;
+}
+
+void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
+{
+ CPUAVRState *env = cs->env_ptr;
+ DisasContext ctx = {
+ .tb = tb,
+ .cs = cs,
+ .env = env,
+ .memidx = 0,
+ .bstate = DISAS_NEXT,
+ .skip_cond = TCG_COND_NEVER,
+ .singlestep = cs->singlestep_enabled,
+ };
+ target_ulong pc_start = tb->pc / 2;
+ int num_insns = 0;
+
+ if (tb->flags & TB_FLAGS_FULL_ACCESS) {
+ /*
+ * This flag is set by ST/LD instruction we will regenerate it ONLY
+ * with mem/cpu memory access instead of mem access
+ */
+ max_insns = 1;
+ }
+ if (ctx.singlestep) {
+ max_insns = 1;
+ }
+
+ gen_tb_start(tb);
+
+ ctx.npc = pc_start;
+ if (tb->flags & TB_FLAGS_SKIP) {
+ ctx.skip_cond = TCG_COND_ALWAYS;
+ ctx.skip_var0 = cpu_skip;
+ }
+
+ do {
+ TCGLabel *skip_label = NULL;
+
+ /* translate current instruction */
+ tcg_gen_insn_start(ctx.npc);
+ num_insns++;
+
+ /*
+ * this is due to some strange GDB behavior
+ * let's assume main has address 0x100
+ * b main - sets breakpoint at address 0x00000100 (code)
+ * b *0x100 - sets breakpoint at address 0x00800100 (data)
+ */
+ if (unlikely(!ctx.singlestep &&
+ (cpu_breakpoint_test(cs, OFFSET_CODE + ctx.npc * 2, BP_ANY) ||
+ cpu_breakpoint_test(cs, OFFSET_DATA + ctx.npc * 2, BP_ANY)))) {
+ canonicalize_skip(&ctx);
+ tcg_gen_movi_tl(cpu_pc, ctx.npc);
+ gen_helper_debug(cpu_env);
+ goto done_generating;
+ }
+
+ /* Conditionally skip the next instruction, if indicated. */
+ if (ctx.skip_cond != TCG_COND_NEVER) {
+ skip_label = gen_new_label();
+ if (ctx.skip_var0 == cpu_skip) {
+ /*
+ * Copy cpu_skip so that we may zero it before the branch.
+ * This ensures that cpu_skip is non-zero after the label
+ * if and only if the skipped insn itself sets a skip.
+ */
+ ctx.free_skip_var0 = true;
+ ctx.skip_var0 = tcg_temp_new();
+ tcg_gen_mov_tl(ctx.skip_var0, cpu_skip);
+ tcg_gen_movi_tl(cpu_skip, 0);
+ }
+ if (ctx.skip_var1 == NULL) {
+ tcg_gen_brcondi_tl(ctx.skip_cond, ctx.skip_var0, 0, skip_label);
+ } else {
+ tcg_gen_brcond_tl(ctx.skip_cond, ctx.skip_var0,
+ ctx.skip_var1, skip_label);
+ ctx.skip_var1 = NULL;
+ }
+ if (ctx.free_skip_var0) {
+ tcg_temp_free(ctx.skip_var0);
+ ctx.free_skip_var0 = false;
+ }
+ ctx.skip_cond = TCG_COND_NEVER;
+ ctx.skip_var0 = NULL;
+ }
+
+ translate(&ctx);
+
+ if (skip_label) {
+ canonicalize_skip(&ctx);
+ gen_set_label(skip_label);
+ if (ctx.bstate == DISAS_NORETURN) {
+ ctx.bstate = DISAS_CHAIN;
+ }
+ }
+ } while (ctx.bstate == DISAS_NEXT
+ && num_insns < max_insns
+ && (ctx.npc - pc_start) * 2 < TARGET_PAGE_SIZE - 4
+ && !tcg_op_buf_full());
+
+ if (tb->cflags & CF_LAST_IO) {
+ gen_io_end();
+ }
+
+ bool nonconst_skip = canonicalize_skip(&ctx);
+
+ switch (ctx.bstate) {
+ case DISAS_NORETURN:
+ assert(!nonconst_skip);
+ break;
+ case DISAS_NEXT:
+ case DISAS_TOO_MANY:
+ case DISAS_CHAIN:
+ if (!nonconst_skip) {
+ /* Note gen_goto_tb checks singlestep. */
+ gen_goto_tb(&ctx, 1, ctx.npc);
+ break;
+ }
+ tcg_gen_movi_tl(cpu_pc, ctx.npc);
+ /* fall through */
+ case DISAS_LOOKUP:
+ if (!ctx.singlestep) {
+ tcg_gen_lookup_and_goto_ptr();
+ break;
+ }
+ /* fall through */
+ case DISAS_EXIT:
+ if (ctx.singlestep) {
+ gen_helper_debug(cpu_env);
+ } else {
+ tcg_gen_exit_tb(NULL, 0);
+ }
+ break;
+ default:
+ g_assert_not_reached();
+ }
+
+done_generating:
+ gen_tb_end(tb, num_insns);
+
+ tb->size = (ctx.npc - pc_start) * 2;
+ tb->icount = num_insns;
+}
+
+void restore_state_to_opc(CPUAVRState *env, TranslationBlock *tb,
+ target_ulong *data)
+{
+ env->pc_w = data[0];
+}