The Hexagon Programmer's Reference Manual says that the exception 0x1e
should be raised upon an unaligned program counter. Let's implement that
and also add tests for both the most common case as well as packets with
multiple change-of-flow instructions.
Signed-off-by: Matheus Tavares Bernardino <quic_mathb...@quicinc.com>
---
target/hexagon/cpu_bits.h | 1 +
target/hexagon/translate.h | 2 ++
target/hexagon/genptr.c | 21 ++++++++++++++++-----
target/hexagon/translate.c | 2 +-
tests/tcg/hexagon/Makefile.target | 13 +++++++++++++
tests/tcg/hexagon/unaligned_pc.S | 10 ++++++++++
tests/tcg/hexagon/unaligned_pc_multi_cof.S | 13 +++++++++++++
7 files changed, 56 insertions(+), 6 deletions(-)
create mode 100644 tests/tcg/hexagon/unaligned_pc.S
create mode 100644 tests/tcg/hexagon/unaligned_pc_multi_cof.S
diff --git a/target/hexagon/cpu_bits.h b/target/hexagon/cpu_bits.h
index 96fef71729..d6900c8bda 100644
--- a/target/hexagon/cpu_bits.h
+++ b/target/hexagon/cpu_bits.h
@@ -23,6 +23,7 @@
#define HEX_EXCP_FETCH_NO_UPAGE 0x012
#define HEX_EXCP_INVALID_PACKET 0x015
#define HEX_EXCP_INVALID_OPCODE 0x015
+#define HEX_EXCP_PC_NOT_ALIGNED 0x01e
#define HEX_EXCP_PRIV_NO_UREAD 0x024
#define HEX_EXCP_PRIV_NO_UWRITE 0x025
diff --git a/target/hexagon/translate.h b/target/hexagon/translate.h
index 4dd59c6726..daf11eb584 100644
--- a/target/hexagon/translate.h
+++ b/target/hexagon/translate.h
@@ -75,6 +75,8 @@ typedef struct DisasContext {
TCGv dczero_addr;
} DisasContext;
+void gen_exception_end_tb(DisasContext *ctx, int excp);
+
static inline void ctx_log_pred_write(DisasContext *ctx, int pnum)
{
if (!test_bit(pnum, ctx->pregs_written)) {
diff --git a/target/hexagon/genptr.c b/target/hexagon/genptr.c
index dbae6c570a..c96edd9379 100644
--- a/target/hexagon/genptr.c
+++ b/target/hexagon/genptr.c
@@ -473,6 +473,7 @@ static void gen_write_new_pc_addr(DisasContext *ctx, TCGv
addr,
TCGCond cond, TCGv pred)
{
TCGLabel *pred_false = NULL;
+ TCGLabel *branch_taken = NULL;
if (cond != TCG_COND_ALWAYS) {
pred_false = gen_new_label();
tcg_gen_brcondi_tl(cond, pred, 0, pred_false);
@@ -480,12 +481,22 @@ static void gen_write_new_pc_addr(DisasContext *ctx, TCGv
addr,
if (ctx->pkt->pkt_has_multi_cof) {
/* If there are multiple branches in a packet, ignore the second one
*/
- tcg_gen_movcond_tl(TCG_COND_NE, hex_gpr[HEX_REG_PC],
- ctx->branch_taken, tcg_constant_tl(0),
- hex_gpr[HEX_REG_PC], addr);
+ branch_taken = gen_new_label();
+ tcg_gen_brcondi_tl(TCG_COND_NE, ctx->branch_taken, 0, branch_taken);
tcg_gen_movi_tl(ctx->branch_taken, 1);
- } else {
- tcg_gen_mov_tl(hex_gpr[HEX_REG_PC], addr);
+ }
+
+ TCGLabel *pc_aligned = gen_new_label();
+ TCGv pc_remainder = tcg_temp_new();
+ tcg_gen_andi_tl(pc_remainder, addr, PCALIGN_MASK);
+ tcg_gen_brcondi_tl(TCG_COND_EQ, pc_remainder, 0, pc_aligned);
+ gen_exception_end_tb(ctx, HEX_EXCP_PC_NOT_ALIGNED);
+ gen_set_label(pc_aligned);
+
+ tcg_gen_mov_tl(hex_gpr[HEX_REG_PC], addr);