x86-64: fix ZMM register state tracking

The three AVX512 state components are entirely independent - one being
in its "init state" has no implication whatsoever on either of the other
two. Fully separate X86_XSTATE_ZMM_H and X86_XSTATE_ZMM handling, to
prevent upper halves of the upper 16 ZMM registers to display as if they
were zero (when they aren't) after e.g. VZEROALL/VZEROUPPER.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 48baa37..6c18be9 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2018-11-08  Jan Beulich  <jbeulich@suse.com>
+
+       * i387-tdep.c (i387_supply_xsave): Split handling of
+       X86_XSTATE_ZMM_H and X86_XSTATE_ZMM.
+       (i387_collect_xsave): Likewise.
+
 2018-11-08  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * riscv-tdep.c (riscv_insn::decode): Update header comment.

diff --git a/gdb/i387-tdep.c b/gdb/i387-tdep.c
index d0f64ad..5d7fe6d 100644 (file)
--- a/gdb/i387-tdep.c
+++ b/gdb/i387-tdep.c
@@ -924,6 +924,12 @@ i387_supply_xsave (struct regcache *regcache, int regnum,
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   const gdb_byte *regs = (const gdb_byte *) xsave;
   int i;
+  /* In 64-bit mode the split between "low" and "high" ZMM registers is at
+     ZMM16.  Outside of 64-bit mode there are no "high" ZMM registers at all.
+     Precalculate the number to be used for the split point, with the all
+     registers in the "low" portion outside of 64-bit mode.  */
+  unsigned int zmm_endlo_regnum = I387_ZMM0H_REGNUM (tdep)
+                                 + std::min (tdep->num_zmm_regs, 16);
   ULONGEST clear_bv;
   static const gdb_byte zero[I386_MAX_REGISTER_SIZE] = { 0 };
   enum
@@ -1002,7 +1008,8 @@ i387_supply_xsave (struct regcache *regcache, int regnum,
       return;
 
     case avx512_zmm_h:
-      if ((clear_bv & (X86_XSTATE_ZMM_H | X86_XSTATE_ZMM)))
+      if ((clear_bv & (regnum < zmm_endlo_regnum ? X86_XSTATE_ZMM_H
+                                                : X86_XSTATE_ZMM)))
        regcache->raw_supply (regnum, zero);
       else
        regcache->raw_supply (regnum,
@@ -1080,21 +1087,17 @@ i387_supply_xsave (struct regcache *regcache, int regnum,
            }
        }
 
-      /* Handle the upper ZMM registers.  */
-      if ((tdep->xcr0 & (X86_XSTATE_ZMM_H | X86_XSTATE_ZMM)))
+      /* Handle the upper halves of the low 8/16 ZMM registers.  */
+      if ((tdep->xcr0 & X86_XSTATE_ZMM_H))
        {
-         if ((clear_bv & (X86_XSTATE_ZMM_H | X86_XSTATE_ZMM)))
+         if ((clear_bv & X86_XSTATE_ZMM_H))
            {
-             for (i = I387_ZMM0H_REGNUM (tdep);
-                  i < I387_ZMMENDH_REGNUM (tdep);
-                  i++)
+             for (i = I387_ZMM0H_REGNUM (tdep); i < zmm_endlo_regnum; i++)
                regcache->raw_supply (i, zero);
            }
          else
            {
-             for (i = I387_ZMM0H_REGNUM (tdep);
-                  i < I387_ZMMENDH_REGNUM (tdep);
-                  i++)
+             for (i = I387_ZMM0H_REGNUM (tdep); i < zmm_endlo_regnum; i++)
                regcache->raw_supply (i,
                                      XSAVE_AVX512_ZMM_H_ADDR (tdep, regs, i));
            }
@@ -1119,11 +1122,13 @@ i387_supply_xsave (struct regcache *regcache, int regnum,
            }
        }
 
-      /* Handle the YMM_AVX512 registers.  */
+      /* Handle the upper 16 ZMM/YMM/XMM registers (if any).  */
       if ((tdep->xcr0 & X86_XSTATE_ZMM))
        {
          if ((clear_bv & X86_XSTATE_ZMM))
            {
+             for (i = zmm_endlo_regnum; i < I387_ZMMENDH_REGNUM (tdep); i++)
+               regcache->raw_supply (i, zero);
              for (i = I387_YMM16H_REGNUM (tdep);
                   i < I387_YMMH_AVX512_END_REGNUM (tdep);
                   i++)
@@ -1135,6 +1140,9 @@ i387_supply_xsave (struct regcache *regcache, int regnum,
            }
          else
            {
+             for (i = zmm_endlo_regnum; i < I387_ZMMENDH_REGNUM (tdep); i++)
+               regcache->raw_supply (i,
+                                     XSAVE_AVX512_ZMM_H_ADDR (tdep, regs, i));
              for (i = I387_YMM16H_REGNUM (tdep);
                   i < I387_YMMH_AVX512_END_REGNUM (tdep);
                   i++)
@@ -1341,6 +1349,9 @@ i387_collect_xsave (const struct regcache *regcache, int regnum,
   gdb_byte raw[I386_MAX_REGISTER_SIZE];
   ULONGEST initial_xstate_bv, clear_bv, xstate_bv = 0;
   unsigned int i;
+  /* See the comment in i387_supply_xsave().  */
+  unsigned int zmm_endlo_regnum = I387_ZMM0H_REGNUM (tdep)
+                                 + std::min (tdep->num_zmm_regs, 16);
   enum
     {
       x87_ctrl_or_mxcsr = 0x1,
@@ -1441,9 +1452,8 @@ i387_collect_xsave (const struct regcache *regcache, int regnum,
             i < I387_MPXEND_REGNUM (tdep); i++)
          memset (XSAVE_MPX_ADDR (tdep, regs, i), 0, 8);
 
-      if ((clear_bv & (X86_XSTATE_ZMM_H | X86_XSTATE_ZMM)))
-       for (i = I387_ZMM0H_REGNUM (tdep);
-            i < I387_ZMMENDH_REGNUM (tdep); i++)
+      if ((clear_bv & X86_XSTATE_ZMM_H))
+       for (i = I387_ZMM0H_REGNUM (tdep); i < zmm_endlo_regnum; i++)
          memset (XSAVE_AVX512_ZMM_H_ADDR (tdep, regs, i), 0, 32);
 
       if ((clear_bv & X86_XSTATE_K))
@@ -1453,6 +1463,8 @@ i387_collect_xsave (const struct regcache *regcache, int regnum,
 
       if ((clear_bv & X86_XSTATE_ZMM))
        {
+         for (i = zmm_endlo_regnum; i < I387_ZMMENDH_REGNUM (tdep); i++)
+           memset (XSAVE_AVX512_ZMM_H_ADDR (tdep, regs, i), 0, 32);
          for (i = I387_YMM16H_REGNUM (tdep);
               i < I387_YMMH_AVX512_END_REGNUM (tdep); i++)
            memset (XSAVE_YMM_AVX512_ADDR (tdep, regs, i), 0, 16);

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 01fc0db..e0bb838 100644 (file)
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-11-08  Jan Beulich  <jbeulich@suse.com>
+
+       * testsuite/gdb.arch/i386-avx512.c,
+       testsuite/gdb.arch/i386-avx512.exp: Add 7th test.
+
 2018-11-08  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * gdb.arch/riscv-reg-aliases.exp: Handle targets without floating

diff --git a/gdb/testsuite/gdb.arch/i386-avx512.c b/gdb/testsuite/gdb.arch/i386-avx512.c
index 9349f09..0e27336 100644 (file)
--- a/gdb/testsuite/gdb.arch/i386-avx512.c
+++ b/gdb/testsuite/gdb.arch/i386-avx512.c
@@ -249,6 +249,13 @@ main (int argc, char **argv)
         move back to array and check values.  */
       move_zmm_data_to_memory ();
       asm ("nop"); /* sixth breakpoint here  */
+
+      asm ("vpternlogd $0xff, %zmm0, %zmm0, %zmm0");
+#ifdef __x86_64__
+      asm ("vpternlogd $0xff, %zmm0, %zmm0, %zmm16");
+#endif
+      asm ("vzeroupper");
+      asm ("nop"); /* seventh breakpoint here  */
     }
 
   return 0;

diff --git a/gdb/testsuite/gdb.arch/i386-avx512.exp b/gdb/testsuite/gdb.arch/i386-avx512.exp
index cd15e05..43fde12 100644 (file)
--- a/gdb/testsuite/gdb.arch/i386-avx512.exp
+++ b/gdb/testsuite/gdb.arch/i386-avx512.exp
@@ -174,3 +174,13 @@ for { set r 0 } { $r < $nr_regs } { incr r } {
         ".. = \\{f = \\{[expr $r + 30], [expr $r.125 + 30], [expr $r.25 + 20], [expr $r.375 + 20], [expr $r.5 + 10], [expr $r.625 + 10], [expr $r.75 + 10], [expr $r.875 + 10]\\}\\}.*" \
         "check contents of zmm_data\[$r\] after writing XMM regs"
 }
+
+gdb_test "break [gdb_get_line_number "seventh breakpoint here"]" \
+    "Breakpoint .* at .*i386-avx512.c.*" \
+    "set seventh breakpoint in main"
+gdb_continue_to_breakpoint "continue to seventh breakpoint in main"
+gdb_test "print \$zmm0.v16_int32" "= {-1, -1, -1, -1, 0 <repeats 12 times>}"
+
+if { $nr_regs >= 16 } {
+    gdb_test "print \$zmm16.v16_int32" "= {-1 <repeats 16 times>}"
+}