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authorAlexander Graf <agraf@suse.de>2013-12-03 15:12:18 +0000
committerPeter Maydell <peter.maydell@linaro.org>2013-12-04 16:04:34 +0000
commitfe676d02edfea029cd0c1755ff24c1b0e1899d98 (patch)
treee5368bc49102541a4d65860fc6d05150c70b849b
parent6aa7e100c21f330bdd55ee63fc8aaa79b84ff77b (diff)
downloadqemu-arm-fe676d02edfea029cd0c1755ff24c1b0e1899d98.tar.gz
target-arm: A64: add support for B and BL insns
Implement the B and BL instructions (PC relative branches and calls). For convenience in managing TCG temporaries which might be generated if a source register is the zero-register XZR, we provide a simple mechanism for creating a new temp which is automatically freed at the end of decode of the instruction. Signed-off-by: Alexander Graf <agraf@suse.de> [claudio: renamed functions, adapted to new decoder layout] Signed-off-by: Claudio Fontana <claudio.fontana@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
-rw-r--r--target-arm/translate-a64.c64
-rw-r--r--target-arm/translate.h3
2 files changed, 65 insertions, 2 deletions
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 1e2b371d4b..bab890d932 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -160,16 +160,71 @@ static void unallocated_encoding(DisasContext *s)
unallocated_encoding(s); \
} while (0);
+static void init_tmp_a64_array(DisasContext *s)
+{
+ int i;
+#ifdef CONFIG_DEBUG_TCG
+ for (i = 0; i < ARRAY_SIZE(s->tmp_a64); i++) {
+ TCGV_UNUSED_I64(s->tmp_a64[i]);
+ }
+#endif
+ s->tmp_a64_count = 0;
+}
+
+static void free_tmp_a64(DisasContext *s)
+{
+ int i;
+ for (i = 0; i < s->tmp_a64_count; i++) {
+ tcg_temp_free_i64(s->tmp_a64[i]);
+ }
+ init_tmp_a64_array(s);
+}
+
+static TCGv_i64 new_tmp_a64(DisasContext *s)
+{
+ assert(s->tmp_a64_count < TMP_A64_MAX);
+ return s->tmp_a64[s->tmp_a64_count++] = tcg_temp_new_i64();
+}
+
+static TCGv_i64 new_tmp_a64_zero(DisasContext *s)
+{
+ TCGv_i64 t = new_tmp_a64(s);
+ tcg_gen_movi_i64(t, 0);
+ return t;
+}
+
+static TCGv_i64 cpu_reg(DisasContext *s, int reg)
+{
+ if (reg == 31) {
+ return new_tmp_a64_zero(s);
+ } else {
+ return cpu_X[reg];
+ }
+}
+
/*
* the instruction disassembly implemented here matches
* the instruction encoding classifications in chapter 3 (C3)
* of the ARM Architecture Reference Manual (DDI0487A_a)
*/
-/* Unconditional branch (immediate) */
+/* C3.2.7 Unconditional branch (immediate)
+ * 31 30 26 25 0
+ * +----+-----------+-------------------------------------+
+ * | op | 0 0 1 0 1 | imm26 |
+ * +----+-----------+-------------------------------------+
+ */
static void disas_uncond_b_imm(DisasContext *s, uint32_t insn)
{
- unsupported_encoding(s, insn);
+ uint64_t addr = s->pc + sextract32(insn, 0, 26) * 4 - 4;
+
+ if (insn & (1 << 31)) {
+ /* C5.6.26 BL Branch with link */
+ tcg_gen_movi_i64(cpu_reg(s, 30), s->pc);
+ }
+
+ /* C5.6.20 B Branch / C5.6.26 BL Branch with link */
+ gen_goto_tb(s, 0, addr);
}
/* Compare & branch (immediate) */
@@ -651,6 +706,9 @@ static void disas_a64_insn(CPUARMState *env, DisasContext *s)
assert(FALSE); /* all 15 cases should be handled above */
break;
}
+
+ /* if we allocated any temporaries, free them here */
+ free_tmp_a64(s);
}
void gen_intermediate_code_internal_a64(ARMCPU *cpu,
@@ -691,6 +749,8 @@ void gen_intermediate_code_internal_a64(ARMCPU *cpu,
dc->vec_len = 0;
dc->vec_stride = 0;
+ init_tmp_a64_array(dc);
+
next_page_start = (pc_start & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
lj = -1;
num_insns = 0;
diff --git a/target-arm/translate.h b/target-arm/translate.h
index 878918176f..23a45daff8 100644
--- a/target-arm/translate.h
+++ b/target-arm/translate.h
@@ -24,6 +24,9 @@ typedef struct DisasContext {
int vec_len;
int vec_stride;
int aarch64;
+#define TMP_A64_MAX 16
+ int tmp_a64_count;
+ TCGv_i64 tmp_a64[TMP_A64_MAX];
} DisasContext;
extern TCGv_ptr cpu_env;