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author | Jason Molenda <jmolenda@apple.com> | 1999-06-28 16:06:02 +0000 |
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committer | Jason Molenda <jmolenda@apple.com> | 1999-06-28 16:06:02 +0000 |
commit | 085dd6e638eca9d348100c8f0e8cae04e20d58a1 (patch) | |
tree | 1e740197cdfedb994222a003ea531ec2febaf173 /gdb/config/convex/Convex.notes | |
parent | 303f629d619e7bf37b97c2af6f72aba488669044 (diff) | |
download | gdb-085dd6e638eca9d348100c8f0e8cae04e20d58a1.zip gdb-085dd6e638eca9d348100c8f0e8cae04e20d58a1.tar.gz gdb-085dd6e638eca9d348100c8f0e8cae04e20d58a1.tar.bz2 |
import gdb-1999-06-28 snapshot
Diffstat (limited to 'gdb/config/convex/Convex.notes')
-rw-r--r-- | gdb/config/convex/Convex.notes | 325 |
1 files changed, 163 insertions, 162 deletions
diff --git a/gdb/config/convex/Convex.notes b/gdb/config/convex/Convex.notes index 28d336b..828778c 100644 --- a/gdb/config/convex/Convex.notes +++ b/gdb/config/convex/Convex.notes @@ -1,163 +1,164 @@ +@c OBSOLETE +@c OBSOLETE @node Convex,,, Top +@c OBSOLETE @appendix Convex-specific info +@c OBSOLETE @cindex Convex notes +@c OBSOLETE +@c OBSOLETE Scalar registers are 64 bits long, which is a pain since +@c OBSOLETE left half of an S register frequently contains noise. +@c OBSOLETE Therefore there are two ways to obtain the value of an S register. +@c OBSOLETE +@c OBSOLETE @table @kbd +@c OBSOLETE @item $s0 +@c OBSOLETE returns the low half of the register as an int +@c OBSOLETE +@c OBSOLETE @item $S0 +@c OBSOLETE returns the whole register as a long long +@c OBSOLETE @end table +@c OBSOLETE +@c OBSOLETE You can print the value in floating point by using @samp{p/f $s0} or @samp{p/f $S0} +@c OBSOLETE to print a single or double precision value. +@c OBSOLETE +@c OBSOLETE @cindex vector registers +@c OBSOLETE Vector registers are handled similarly, with @samp{$V0} denoting the whole +@c OBSOLETE 64-bit register and @kbd{$v0} denoting the 32-bit low half; @samp{p/f $v0} +@c OBSOLETE or @samp{p/f $V0} can be used to examine the register in floating point. +@c OBSOLETE The length of the vector registers is taken from @samp{$vl}. +@c OBSOLETE +@c OBSOLETE Individual elements of a vector register are denoted in the obvious way; +@c OBSOLETE @samp{print $v3[9]} prints the tenth element of register @kbd{v3}, and +@c OBSOLETE @samp{set $v3[9] = 1234} alters it. +@c OBSOLETE +@c OBSOLETE @kbd{$vl} and @kbd{$vs} are int, and @kbd{$vm} is an int vector. +@c OBSOLETE Elements of @kbd{$vm} can't be assigned to. +@c OBSOLETE +@c OBSOLETE @cindex communication registers +@c OBSOLETE @kindex info comm-registers +@c OBSOLETE Communication registers have names @kbd{$C0 .. $C63}, with @kbd{$c0 .. $c63} +@c OBSOLETE denoting the low-order halves. @samp{info comm-registers} will print them +@c OBSOLETE all out, and tell which are locked. (A communication register is +@c OBSOLETE locked when a value is sent to it, and unlocked when the value is +@c OBSOLETE received.) Communication registers are, of course, global to all +@c OBSOLETE threads, so it does not matter what the currently selected thread is. +@c OBSOLETE @samp{info comm-reg @var{name}} prints just that one communication +@c OBSOLETE register; @samp{name} may also be a communication register number +@c OBSOLETE @samp{nn} or @samp{0xnn}. +@c OBSOLETE @samp{info comm-reg @var{address}} prints the contents of the resource +@c OBSOLETE structure at that address. +@c OBSOLETE +@c OBSOLETE @kindex info psw +@c OBSOLETE The command @samp{info psw} prints the processor status word @kbd{$ps} +@c OBSOLETE bit by bit. +@c OBSOLETE +@c OBSOLETE @kindex set base +@c OBSOLETE GDB normally prints all integers in base 10, but the leading +@c OBSOLETE @kbd{0x80000000} of pointers is intolerable in decimal, so the default +@c OBSOLETE output radix has been changed to try to print addresses appropriately. +@c OBSOLETE The @samp{set base} command can be used to change this. +@c OBSOLETE +@c OBSOLETE @table @code +@c OBSOLETE @item set base 10 +@c OBSOLETE Integer values always print in decimal. +@c OBSOLETE +@c OBSOLETE @item set base 16 +@c OBSOLETE Integer values always print in hex. +@c OBSOLETE +@c OBSOLETE @item set base +@c OBSOLETE Go back to the initial state, which prints integer values in hex if they +@c OBSOLETE look like pointers (specifically, if they start with 0x8 or 0xf in the +@c OBSOLETE stack), otherwise in decimal. +@c OBSOLETE @end table +@c OBSOLETE +@c OBSOLETE @kindex set pipeline +@c OBSOLETE When an exception such as a bus error or overflow happens, usually the PC +@c OBSOLETE is several instructions ahead by the time the exception is detected. +@c OBSOLETE The @samp{set pipe} command will disable this. +@c OBSOLETE +@c OBSOLETE @table @code +@c OBSOLETE @item set pipeline off +@c OBSOLETE Forces serial execution of instructions; no vector chaining and no +@c OBSOLETE scalar instruction overlap. With this, exceptions are detected with +@c OBSOLETE the PC pointing to the instruction after the one in error. +@c OBSOLETE +@c OBSOLETE @item set pipeline on +@c OBSOLETE Returns to normal, fast, execution. This is the default. +@c OBSOLETE @end table +@c OBSOLETE +@c OBSOLETE @cindex parallel +@c OBSOLETE In a parallel program, multiple threads may be executing, each +@c OBSOLETE with its own registers, stack, and local memory. When one of them +@c OBSOLETE hits a breakpoint, that thread is selected. Other threads do +@c OBSOLETE not run while the thread is in the breakpoint. +@c OBSOLETE +@c OBSOLETE @kindex 1cont +@c OBSOLETE The selected thread can be single-stepped, given signals, and so +@c OBSOLETE on. Any other threads remain stopped. When a @samp{cont} command is given, +@c OBSOLETE all threads are resumed. To resume just the selected thread, use +@c OBSOLETE the command @samp{1cont}. +@c OBSOLETE +@c OBSOLETE @kindex thread +@c OBSOLETE The @samp{thread} command will show the active threads and the +@c OBSOLETE instruction they are about to execute. The selected thread is marked +@c OBSOLETE with an asterisk. The command @samp{thread @var{n}} will select thread @var{n}, +@c OBSOLETE shifting the debugger's attention to it for single-stepping, +@c OBSOLETE registers, local memory, and so on. +@c OBSOLETE +@c OBSOLETE @kindex info threads +@c OBSOLETE The @samp{info threads} command will show what threads, if any, have +@c OBSOLETE invisibly hit breakpoints or signals and are waiting to be noticed. +@c OBSOLETE +@c OBSOLETE @kindex set parallel +@c OBSOLETE The @samp{set parallel} command controls how many threads can be active. +@c OBSOLETE +@c OBSOLETE @table @code +@c OBSOLETE @item set parallel off +@c OBSOLETE One thread. Requests by the program that other threads join in +@c OBSOLETE (spawn and pfork instructions) do not cause other threads to start up. +@c OBSOLETE This does the same thing as the @samp{limit concurrency 1} command. +@c OBSOLETE +@c OBSOLETE @item set parallel fixed +@c OBSOLETE All CPUs are assigned to your program whenever it runs. When it +@c OBSOLETE executes a pfork or spawn instruction, it begins parallel execution +@c OBSOLETE immediately. This does the same thing as the @samp{mpa -f} command. +@c OBSOLETE +@c OBSOLETE @item set parallel on +@c OBSOLETE One or more threads. Spawn and pfork cause CPUs to join in when and if +@c OBSOLETE they are free. This is the default. It is very good for system +@c OBSOLETE throughput, but not very good for finding bugs in parallel code. If you +@c OBSOLETE suspect a bug in parallel code, you probably want @samp{set parallel fixed.} +@c OBSOLETE @end table +@c OBSOLETE +@c OBSOLETE @subsection Limitations +@c OBSOLETE +@c OBSOLETE WARNING: Convex GDB evaluates expressions in long long, because S +@c OBSOLETE registers are 64 bits long. However, GDB expression semantics are not +@c OBSOLETE exactly C semantics. This is a bug, strictly speaking, but it's not one I +@c OBSOLETE know how to fix. If @samp{x} is a program variable of type int, then it +@c OBSOLETE is also type int to GDB, but @samp{x + 1} is long long, as is @samp{x + y} +@c OBSOLETE or any other expression requiring computation. So is the expression +@c OBSOLETE @samp{1}, or any other constant. You only really have to watch out for +@c OBSOLETE calls. The innocuous expression @samp{list_node (0x80001234)} has an +@c OBSOLETE argument of type long long. You must explicitly cast it to int. +@c OBSOLETE +@c OBSOLETE It is not possible to continue after an uncaught fatal signal by using +@c OBSOLETE @samp{signal 0}, @samp{return}, @samp{jump}, or anything else. The difficulty is with +@c OBSOLETE Unix, not GDB. +@c OBSOLETE +@c OBSOLETE I have made no big effort to make such things as single-stepping a +@c OBSOLETE @kbd{join} instruction do something reasonable. If the program seems to +@c OBSOLETE hang when doing this, type @kbd{ctrl-c} and @samp{cont}, or use +@c OBSOLETE @samp{thread} to shift to a live thread. Single-stepping a @kbd{spawn} +@c OBSOLETE instruction apparently causes new threads to be born with their T bit set; +@c OBSOLETE this is not handled gracefully. When a thread has hit a breakpoint, other +@c OBSOLETE threads may have invisibly hit the breakpoint in the background; if you +@c OBSOLETE clear the breakpoint gdb will be surprised when threads seem to continue +@c OBSOLETE to stop at it. All of these situations produce spurious signal 5 traps; +@c OBSOLETE if this happens, just type @samp{cont}. If it becomes a nuisance, use +@c OBSOLETE @samp{handle 5 nostop}. (It will ask if you are sure. You are.) +@c OBSOLETE +@c OBSOLETE There is no way in GDB to store a float in a register, as with +@c OBSOLETE @kbd{set $s0 = 3.1416}. The identifier @kbd{$s0} denotes an integer, +@c OBSOLETE and like any C expression which assigns to an integer variable, the +@c OBSOLETE right-hand side is casted to type int. If you should need to do +@c OBSOLETE something like this, you can assign the value to @kbd{@{float@} ($sp-4)} +@c OBSOLETE and then do @kbd{set $s0 = $sp[-4]}. Same deal with @kbd{set $v0[69] = 6.9}. -@node Convex,,, Top -@appendix Convex-specific info -@cindex Convex notes - -Scalar registers are 64 bits long, which is a pain since -left half of an S register frequently contains noise. -Therefore there are two ways to obtain the value of an S register. - -@table @kbd -@item $s0 -returns the low half of the register as an int - -@item $S0 -returns the whole register as a long long -@end table - -You can print the value in floating point by using @samp{p/f $s0} or @samp{p/f $S0} -to print a single or double precision value. - -@cindex vector registers -Vector registers are handled similarly, with @samp{$V0} denoting the whole -64-bit register and @kbd{$v0} denoting the 32-bit low half; @samp{p/f $v0} -or @samp{p/f $V0} can be used to examine the register in floating point. -The length of the vector registers is taken from @samp{$vl}. - -Individual elements of a vector register are denoted in the obvious way; -@samp{print $v3[9]} prints the tenth element of register @kbd{v3}, and -@samp{set $v3[9] = 1234} alters it. - -@kbd{$vl} and @kbd{$vs} are int, and @kbd{$vm} is an int vector. -Elements of @kbd{$vm} can't be assigned to. - -@cindex communication registers -@kindex info comm-registers -Communication registers have names @kbd{$C0 .. $C63}, with @kbd{$c0 .. $c63} -denoting the low-order halves. @samp{info comm-registers} will print them -all out, and tell which are locked. (A communication register is -locked when a value is sent to it, and unlocked when the value is -received.) Communication registers are, of course, global to all -threads, so it does not matter what the currently selected thread is. -@samp{info comm-reg @var{name}} prints just that one communication -register; @samp{name} may also be a communication register number -@samp{nn} or @samp{0xnn}. -@samp{info comm-reg @var{address}} prints the contents of the resource -structure at that address. - -@kindex info psw -The command @samp{info psw} prints the processor status word @kbd{$ps} -bit by bit. - -@kindex set base -GDB normally prints all integers in base 10, but the leading -@kbd{0x80000000} of pointers is intolerable in decimal, so the default -output radix has been changed to try to print addresses appropriately. -The @samp{set base} command can be used to change this. - -@table @code -@item set base 10 -Integer values always print in decimal. - -@item set base 16 -Integer values always print in hex. - -@item set base -Go back to the initial state, which prints integer values in hex if they -look like pointers (specifically, if they start with 0x8 or 0xf in the -stack), otherwise in decimal. -@end table - -@kindex set pipeline -When an exception such as a bus error or overflow happens, usually the PC -is several instructions ahead by the time the exception is detected. -The @samp{set pipe} command will disable this. - -@table @code -@item set pipeline off -Forces serial execution of instructions; no vector chaining and no -scalar instruction overlap. With this, exceptions are detected with -the PC pointing to the instruction after the one in error. - -@item set pipeline on -Returns to normal, fast, execution. This is the default. -@end table - -@cindex parallel -In a parallel program, multiple threads may be executing, each -with its own registers, stack, and local memory. When one of them -hits a breakpoint, that thread is selected. Other threads do -not run while the thread is in the breakpoint. - -@kindex 1cont -The selected thread can be single-stepped, given signals, and so -on. Any other threads remain stopped. When a @samp{cont} command is given, -all threads are resumed. To resume just the selected thread, use -the command @samp{1cont}. - -@kindex thread -The @samp{thread} command will show the active threads and the -instruction they are about to execute. The selected thread is marked -with an asterisk. The command @samp{thread @var{n}} will select thread @var{n}, -shifting the debugger's attention to it for single-stepping, -registers, local memory, and so on. - -@kindex info threads -The @samp{info threads} command will show what threads, if any, have -invisibly hit breakpoints or signals and are waiting to be noticed. - -@kindex set parallel -The @samp{set parallel} command controls how many threads can be active. - -@table @code -@item set parallel off -One thread. Requests by the program that other threads join in -(spawn and pfork instructions) do not cause other threads to start up. -This does the same thing as the @samp{limit concurrency 1} command. - -@item set parallel fixed -All CPUs are assigned to your program whenever it runs. When it -executes a pfork or spawn instruction, it begins parallel execution -immediately. This does the same thing as the @samp{mpa -f} command. - -@item set parallel on -One or more threads. Spawn and pfork cause CPUs to join in when and if -they are free. This is the default. It is very good for system -throughput, but not very good for finding bugs in parallel code. If you -suspect a bug in parallel code, you probably want @samp{set parallel fixed.} -@end table - -@subsection Limitations - -WARNING: Convex GDB evaluates expressions in long long, because S -registers are 64 bits long. However, GDB expression semantics are not -exactly C semantics. This is a bug, strictly speaking, but it's not one I -know how to fix. If @samp{x} is a program variable of type int, then it -is also type int to GDB, but @samp{x + 1} is long long, as is @samp{x + y} -or any other expression requiring computation. So is the expression -@samp{1}, or any other constant. You only really have to watch out for -calls. The innocuous expression @samp{list_node (0x80001234)} has an -argument of type long long. You must explicitly cast it to int. - -It is not possible to continue after an uncaught fatal signal by using -@samp{signal 0}, @samp{return}, @samp{jump}, or anything else. The difficulty is with -Unix, not GDB. - -I have made no big effort to make such things as single-stepping a -@kbd{join} instruction do something reasonable. If the program seems to -hang when doing this, type @kbd{ctrl-c} and @samp{cont}, or use -@samp{thread} to shift to a live thread. Single-stepping a @kbd{spawn} -instruction apparently causes new threads to be born with their T bit set; -this is not handled gracefully. When a thread has hit a breakpoint, other -threads may have invisibly hit the breakpoint in the background; if you -clear the breakpoint gdb will be surprised when threads seem to continue -to stop at it. All of these situations produce spurious signal 5 traps; -if this happens, just type @samp{cont}. If it becomes a nuisance, use -@samp{handle 5 nostop}. (It will ask if you are sure. You are.) - -There is no way in GDB to store a float in a register, as with -@kbd{set $s0 = 3.1416}. The identifier @kbd{$s0} denotes an integer, -and like any C expression which assigns to an integer variable, the -right-hand side is casted to type int. If you should need to do -something like this, you can assign the value to @kbd{@{float@} ($sp-4)} -and then do @kbd{set $s0 = $sp[-4]}. Same deal with @kbd{set $v0[69] = 6.9}. |