[PATCH v6 2/8] perf cs-etm: Refactor instruction size handling

[Leo Yan]

From: Leo Yan <leo.yan at linaro.org>

This patch introduces a new function cs_etm__instr_size() to calculate
the instruction size based on ISA type and instruction address.

Given the trace data can be MB and most likely that will be A64/A32 on
a lot of platforms, cs_etm__instr_addr() keeps a single ISA type check
for A64/A32 and executes an optimized calculation (addr + offset * 4).

Signed-off-by: Leo Yan <leo.yan at linaro.org>
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 tools/perf/util/cs-etm.c | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index ab79d08f5a6095448470e2c3ec85ff3db2fb5634..5bff8811d61e423463b7bd4e20d599d5b5307a1a 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -1347,6 +1347,17 @@ static inline int cs_etm__t32_instr_size(struct cs_etm_queue *etmq,
 	return ((instrBytes[1] & 0xF8) >= 0xE8) ? 4 : 2;
 }
 
+static inline int cs_etm__instr_size(struct cs_etm_queue *etmq,
+				     u8 trace_chan_id,
+				     enum cs_etm_isa isa, u64 addr)
+{
+	if (isa == CS_ETM_ISA_T32)
+		return cs_etm__t32_instr_size(etmq, trace_chan_id, addr);
+
+	/* Otherwise, 4-byte instruction size for A32/A64 */
+	return 4;
+}
+
 static inline u64 cs_etm__first_executed_instr(struct cs_etm_packet *packet)
 {
 	/*
@@ -1375,19 +1386,18 @@ static inline u64 cs_etm__instr_addr(struct cs_etm_queue *etmq,
 				     const struct cs_etm_packet *packet,
 				     u64 offset)
 {
-	if (packet->isa == CS_ETM_ISA_T32) {
-		u64 addr = packet->start_addr;
+	u64 addr = packet->start_addr;
 
-		while (offset) {
-			addr += cs_etm__t32_instr_size(etmq,
-						       trace_chan_id, addr);
-			offset--;
-		}
-		return addr;
-	}
+	/* 4-byte instruction size for A32/A64 */
+	if (packet->isa == CS_ETM_ISA_A64 || packet->isa == CS_ETM_ISA_A32)
+		return addr + offset * 4;
 
-	/* Assume a 4 byte instruction size (A32/A64) */
-	return packet->start_addr + offset * 4;
+	while (offset) {
+		addr += cs_etm__instr_size(etmq, trace_chan_id,
+					   packet->isa, addr);
+		offset--;
+	}
+	return addr;
 }
 
 static void cs_etm__update_last_branch_rb(struct cs_etm_queue *etmq,
@@ -1540,16 +1550,8 @@ static void cs_etm__copy_insn(struct cs_etm_queue *etmq,
 		return;
 	}
 
-	/*
-	 * T32 instruction size might be 32-bit or 16-bit, decide by calling
-	 * cs_etm__t32_instr_size().
-	 */
-	if (packet->isa == CS_ETM_ISA_T32)
-		sample->insn_len = cs_etm__t32_instr_size(etmq, trace_chan_id,
-							  sample->ip);
-	/* Otherwise, A64 and A32 instruction size are always 32-bit. */
-	else
-		sample->insn_len = 4;
+	sample->insn_len = cs_etm__instr_size(etmq, trace_chan_id,
+					      packet->isa, sample->ip);
 
 	cs_etm__mem_access(etmq, trace_chan_id, sample->ip, sample->insn_len,
 			   (void *)sample->insn, 0);

-- 
2.34.1