* sparc-stub.c (trap_low): Make trap handler work for arbitrary

	numbers of register windows.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 676a46ac44ea105ddf4e7e591fbb168f32edc27a..5ed86ecc8a2d4c9095680774554a1c5b4cc33052 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -6,6 +6,9 @@ Wed Feb 23 16:28:55 1994  Jeffrey A. Law  (law@cygnus.com)
 
 Wed Feb 23 16:21:25 1994  Stu Grossman  (grossman at cygnus.com)
 
+       * sparc-stub.c (trap_low):  Make trap handler work for arbitrary
+       numbers of register windows.
+
        * sparclite/hello.c:  Add factorial function for testing.
        * salib.c:  Use macros instead of constants for I/O addresses to
        make 931 support easier.

diff --git a/gdb/sparc-stub.c b/gdb/sparc-stub.c
index 5de62a339e4e49fbe4233f301dd2d471ca59e535..d2e7b438a8dc658d96f4779e59472198bf8bdadb 100644 (file)
--- a/gdb/sparc-stub.c
+++ b/gdb/sparc-stub.c
@@ -157,9 +157,27 @@ _trap_low:
 
        mov     %g1, %l4                ! Save g1, we use it to hold the wim
        srl     %l3, 1, %g1             ! Rotate wim right
-       sll     %l3, 8-1, %l5
-       or      %l5, %g1, %g1
+       tst     %g1
+       bg      good_wim                ! Branch if new wim is non-zero
 
+! At this point, we need to bring a 1 into the high order bit of the wim.
+! Since we don't want to make any assumptions about the number of register
+! windows, we figure it out dynamically so as to setup the wim correctly.
+
+       not     %g1                     ! Fill g1 with ones
+       mov     %g1, %wim               ! Fill the wim with ones
+       nop
+       nop
+       nop
+       mov     %wim, %g1               ! Read back the wim
+       inc     %g1                     ! Now g1 has 1 just to left of wim
+       srl     %g1, 1, %g1             ! Now put 1 at top of wim
+       mov     %g0, %wim               ! Clear wim so that subsequent save
+       nop                             !  won't trap
+       nop
+       nop
+
+good_wim:
        save    %g0, %g0, %g0           ! Slip into next window
        mov     %g1, %wim               ! Install the new wim
 
@@ -758,7 +776,7 @@ handle_exception (registers)
          break;
 #if 0
        case 't':               /* Test feature */
-         asm (" std %f31,[%sp]");
+         asm (" std %f30,[%sp]");
          break;
 #endif
        case 'r':               /* Reset */