[PATCH 3/3] gdb/record: add support to AVX unpack instructions

[Guinevere Larsen <blarsen@redhat.com>]

This commit adds support to recording instructions to unpack high
or low data from XMM registers, identified by the mnemonics in the
form: VPUNPCK [L|H] [BW|WD|DQ|QDQ].
All these instructions are encoded the exact same way, and only affect
the destination register, making them trivial to implement together.

It also updates the test gdb.reverse/i386-avx-reverse.exp to test these
new instructions.
---
 gdb/i386-tdep.c                               | 12 ++++++
 gdb/testsuite/gdb.reverse/i386-avx-reverse.c  | 37 +++++++++++++++++++
 .../gdb.reverse/i386-avx-reverse.exp          | 26 +++++++++++++
 3 files changed, 75 insertions(+)

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index d2848970ec4..250aff73389 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -5057,6 +5057,18 @@ i386_record_vex (struct i386_record_s *ir, uint8_t vex_w, uint8_t vex_r,
 	}
       break;
 
+    case 0x60:	/* VPUNPCKLBW  */
+    case 0x61:	/* VPUNPCKLWD  */
+    case 0x62:	/* VPUNPCKLDQ  */
+    case 0x6c:	/* VPUNPCKLQDQ */
+    case 0x68:	/* VPUNPCKHBW  */
+    case 0x69:	/* VPUNPCKHWD  */
+    case 0x6a:	/* VPUNPCKHDQ  */
+    case 0x6d:	/* VPUNPCKHQDQ */
+      i386_record_modrm (ir);
+      record_full_arch_list_add_reg (ir->regcache, ir->regmap[X86_RECORD_XMM0_REGNUM] + ir->reg + vex_r * 8);
+      break;
+
     default:
       gdb_printf (gdb_stderr,
 		  _("Process record does not support VEX instruction 0x%02x "
diff --git a/gdb/testsuite/gdb.reverse/i386-avx-reverse.c b/gdb/testsuite/gdb.reverse/i386-avx-reverse.c
index 216b593736b..4a4785ee99e 100644
--- a/gdb/testsuite/gdb.reverse/i386-avx-reverse.c
+++ b/gdb/testsuite/gdb.reverse/i386-avx-reverse.c
@@ -70,6 +70,40 @@ vmov_test ()
   asm volatile ("vmovq %0, %%xmm15": "=m" (buf1));
 } /* end vmov_test */
 
+/* Test if we can properly record (and undo) vpunpck style instructions.
+   Most tests will use xmm0 and xmm1 as sources. The registers xmm15 and xmm2
+   are used as destination to ensure we're reading the VEX.R bit correctly.  */
+void
+vpunpck_test  ()
+{
+  /* Using GDB, load these values onto registers, for ease of testing.
+     xmm0.uint128 = 0x1f1e1d1c1b1a19181716151413121110
+     xmm1.uint128 = 0x2f2e2d2c2b2a29282726252423222120
+     so that's easy to confirm that the unpacking went as expected.  */
+
+  /* 17 27 16 26 15 25 14 24 ...*/
+  asm volatile ("vpunpcklbw  %xmm0, %xmm1, %xmm15");
+  /* 17 16 27 26 15 14 25 24 ...*/
+  asm volatile ("vpunpcklwd  %0, %%xmm1, %%xmm15"
+      : : "m" (global_buf0));
+  /* 17 16 15 14 27 26 25 24 ...*/
+  asm volatile ("vpunpckldq  %0, %%xmm1,  %%xmm2"
+      : : "m" (global_buf0));
+  /* 17 16 15 14 13 12 11 10 ...*/
+  asm volatile ("vpunpcklqdq %xmm0, %xmm1, %xmm2");
+
+  /* 17 27 16 26 15 25 14 24 ...*/
+  asm volatile ("vpunpckhbw  %xmm0, %xmm1, %xmm15");
+  /* 17 16 27 26 15 14 25 24 ...*/
+  asm volatile ("vpunpckhwd  %0, %%xmm1, %%xmm15"
+      : : "m" (global_buf0));
+  /* 17 16 15 14 27 26 25 24 ...*/
+  asm volatile ("vpunpckhdq  %0, %%xmm1,  %%xmm2"
+      : : "m" (global_buf0));
+  /* 17 16 15 14 13 12 11 10 ...*/
+  asm volatile ("vpunpckhqdq %xmm0, %xmm1, %xmm2");
+} /* end vpunpck_test */
+
 int
 main ()
 {
@@ -82,9 +116,12 @@ main ()
     }
   /* Zero relevant xmm registers, se we know what to look for.  */
   asm volatile ("vmovq %0, %%xmm0": : "m" (global_buf1));
+  asm volatile ("vmovq %0, %%xmm1": : "m" (global_buf1));
+  asm volatile ("vmovq %0, %%xmm2": : "m" (global_buf1));
   asm volatile ("vmovq %0, %%xmm15": : "m" (global_buf1));
 
   /* Start recording. */
   vmov_test ();
+  vpunpck_test ();
   return 0;	/* end of main */
 }
diff --git a/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp b/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp
index 42ddc3a6526..c5e82eaeca6 100644
--- a/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp
+++ b/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp
@@ -169,3 +169,29 @@ if {[record_full_function "vmov"] == true} {
 gdb_test "record stop" "Process record is stopped.*" \
     "delete history for vmov_test"
 gdb_test "finish" "Run till exit from.*vmov_test.*" "leaving vmov_test"
+
+# Starting vpunpck tests.
+gdb_test "step" "vpunpck_test \\\(\\\) at .*" "entering vpunpck_test function"
+gdb_test_no_output "set \$xmm0.v2_int64 = {0x1716151413121110, 0x1f1e1d1c1b1a1918}"
+gdb_test_no_output "set \$xmm1.v2_int64 = {0x2726252423222120, 0x2f2e2d2c2b2a2928}"
+gdb_test_no_output "set \$xmm2.uint128 = 0x0"
+gdb_test_no_output "set \$xmm15.uint128 = 0x0"
+if {[record_full_function "vpunpck"] == true} {
+    test_one_register "vpunpckhqdq" "xmm2" "0x"
+    test_one_register "vpunpckhdq" "xmm2" "0x"
+    test_one_register "vpunpckhwd" "xmm15" "0x"
+    test_one_register "vpunpckhbw" "xmm15" "0x"
+
+    test_one_register "vpunpcklqdq" "xmm2" "0x17161514272625241312111023222120"
+    test_one_register "vpunpckldq" "xmm2" "0x0"
+    test_one_register "vpunpcklwd" "xmm15" "0x17271626152514241323122211211020"
+    test_one_register "vpunpcklbw" "xmm15" "0x0"
+} else {
+    untested "couldn't test vpunpck tests"
+}
+
+# Move to the end of vmov_test to set up next.
+# Stop recording in case of recording errors.
+gdb_test "record stop" "Process record is stopped.*" \
+    "delete history for vpunpck_test"
+gdb_test "finish" "Run till exit from.*vpunpck_test.*" "leaving vpunpck_test"
-- 
2.45.1