[PATCH] perf/annotate: Fix branch instruction with multiple operands

[Kim Phillips <kim.phillips@arm.com>]

From: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>

Perf annotate is dropping the cr* fields from branch instructions.
Fix it by adding support to display branch instructions having
multiple operands.

Objdump of int_sqrt:

 20.36 | c0000000004d2694:   subf   r10,r10,r3
       | c0000000004d2698: v bgt    cr6,c0000000004d26a0 <int_sqrt+0x40>
  1.82 | c0000000004d269c:   mr     r3,r10
 29.18 | c0000000004d26a0:   mr     r10,r8
       | c0000000004d26a4: v bgt    cr7,c0000000004d26ac <int_sqrt+0x4c>
       | c0000000004d26a8:   mr     r10,r7

Before Patch:

 20.36 |       subf   r10,r10,r3
       |     v bgt    40
  1.82 |       mr     r3,r10
 29.18 | 40:   mr     r10,r8
       |     v bgt    4c
       |       mr     r10,r7

After patch:

 20.36 |       subf   r10,r10,r3
       |     v bgt    cr6,40
  1.82 |       mr     r3,r10
 29.18 | 40:   mr     r10,r8
       |     v bgt    cr7,4c
       |       mr     r10,r7

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>

Reduced to keep only one scnprintf and supplemented for AArch64
conditional branch instructions:

Non-simplified (raw objdump) view:

       │ffff0000083cd11c: ↑ cbz    w0, ffff0000083cd100 <security_fil▒
...
  4.44 │ffff000│083cd134: ↓ tbnz   w0, #26, ffff0000083cd190 <securit▒
...
  1.37 │ffff000│083cd144: ↓ tbnz   w22, #5, ffff0000083cd1a4 <securit▒
       │ffff000│083cd148:   mov    w19, #0x20000                   //▒
  1.02 │ffff000│083cd14c: ↓ tbz    w22, #2, ffff0000083cd1ac <securit▒
...
  0.68 │ffff000└──3cd16c: ↑ cbnz   w0, ffff0000083cd120 <security_fil▒

Simplified, before this patch:

       │    ↑ cbz    40                                              ▒
...
  4.44 │   │↓ tbnz   w0, #26, ffff0000083cd190 <security_file_permiss▒
...
  1.37 │   │↓ tbnz   w22, #5, ffff0000083cd1a4 <security_file_permiss▒
       │   │  mov    w19, #0x20000                   // #131072      ▒
  1.02 │   │↓ tbz    w22, #2, ffff0000083cd1ac <security_file_permiss▒
...
  0.68 │   └──cbnz   60                                              ▒

the cbz operand is missing, and the tbz doesn't get simplified processing
at all because the address-get function failed to match an address.

Simplified, After this patch applied:

       │    ↑ cbz    w0, 40                                          ▒
...
  4.44 │   │↓ tbnz   w0, #26, d0                                     ▒
...
  1.37 │   │↓ tbnz   w22, #5, e4                                     ▒
       │   │  mov    w19, #0x20000                   // #131072      ▒
  1.02 │   │↓ tbz    w22, #2, ec                                     ▒
...
  0.68 │   └──cbnz   w0, 60                                          ▒

Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Reported-by: Robin Murphy <robin.murphy@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
---

Sorry if any confusion: I thought it easier to merge the changes into
one patch and resubmit it.  The only patch to apply is this one; I
tested on powerpc and x86_64 also, and they still work as with Ravi's
original patch (this one just adds the ARM fixes, and slightly
optimizes Ravi's original patch).

 tools/perf/util/annotate.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 683f8340460c..3174930e7cea 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -239,10 +239,20 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op
 	const char *s = strchr(ops->raw, '+');
 	const char *c = strchr(ops->raw, ',');
 
-	if (c++ != NULL)
+	/*
+	 * skip over possible up to 2 operands to get to address, e.g.:
+	 * tbnz	 w0, #26, ffff0000083cd190 <security_file_permission+0xd0>
+	 */
+	if (c++ != NULL) {
 		ops->target.addr = strtoull(c, NULL, 16);
-	else
+		if (!ops->target.addr) {
+			c = strchr(c, ',');
+			if (c++ != NULL)
+				ops->target.addr = strtoull(c, NULL, 16);
+		}
+	} else {
 		ops->target.addr = strtoull(ops->raw, NULL, 16);
+	}
 
 	if (s++ != NULL) {
 		ops->target.offset = strtoull(s, NULL, 16);
@@ -257,10 +267,27 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op
 static int jump__scnprintf(struct ins *ins, char *bf, size_t size,
 			   struct ins_operands *ops)
 {
+	const char *c = strchr(ops->raw, ',');
+
 	if (!ops->target.addr || ops->target.offset < 0)
 		return ins__raw_scnprintf(ins, bf, size, ops);
 
-	return scnprintf(bf, size, "%-6.6s %" PRIx64, ins->name, ops->target.offset);
+	if (c != NULL) {
+		const char *c2 = strchr(c + 1, ',');
+
+		/* check for 3-op insn */
+		if (c2 != NULL)
+			c = c2;
+		c++;
+
+		/* mirror arch objdump's space-after-comma style */
+		if (*c == ' ')
+			c++;
+	}
+
+	return scnprintf(bf, size, "%-6.6s %.*s%" PRIx64,
+			 ins->name, c ? c - ops->raw : 0, ops->raw,
+			 ops->target.offset);
 }
 
 static struct ins_ops jump_ops = {
-- 
2.11.0