From dd99f8e4b2fba127ae6b01a832094d5d0ec6cb03 Mon Sep 17 00:00:00 2001 From: Jim Kingdon Date: Fri, 9 Jul 1993 03:53:46 +0000 Subject: [PATCH] * sparc-tdep.c (sparc_push_dummy_frame): Skip all the do_save_insn stuff, just write the sp and fp. (sparc_pop_frame): Skip the do_restore_insn; we already restore the sp with the other out registers. --- gdb/ChangeLog | 5 ++ gdb/sparc-tdep.c | 189 +++++++++++++++-------------------------------- 2 files changed, 63 insertions(+), 131 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 44390a1118..086d7cd241 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,10 @@ Thu Jul 8 14:48:54 1993 Jim Kingdon (kingdon@lioth.cygnus.com) + * sparc-tdep.c (sparc_push_dummy_frame): Skip all the do_save_insn + stuff, just write the sp and fp. + (sparc_pop_frame): Skip the do_restore_insn; we already restore + the sp with the other out registers. + * hppa-tdep.c (hppa_push_arguments): Allocate enough space for arguments. diff --git a/gdb/sparc-tdep.c b/gdb/sparc-tdep.c index dceaec5472..5bfd263b5b 100644 --- a/gdb/sparc-tdep.c +++ b/gdb/sparc-tdep.c @@ -214,115 +214,6 @@ setup_arbitrary_frame (argc, argv) return fid; } -/* This code was written by Gary Beihl (beihl@mcc.com). - It was modified by Michael Tiemann (tiemann@corto.inria.fr). */ - -/* - * This routine appears to be passed a size by which to increase the - * stack. It then executes a save instruction in the inferior to - * increase the stack by this amount. Only the register window system - * should be affected by this; the program counter & etc. will not be. - * - * This instructions used for this purpose are: - * - * sethi %hi(0x0),g1 * - * add g1,0x1ee0,g1 * - * save sp,g1,sp - * sethi %hi(0x0),g1 * - * add g1,0x1ee0,g1 * - * t g0,0x1,o0 - * sethi %hi(0x0),g0 (nop) - * - * I presume that these set g1 to be the negative of the size, do a - * save (putting the stack pointer at sp - size) and restore the - * original contents of g1. A * indicates that the actual value of - * the instruction is modified below. - */ -static unsigned int save_insn_opcodes[] = { - 0x03000000, 0x82007ee0, 0x9de38001, 0x03000000, - 0x82007ee0, 0x91d02001, 0x01000000 }; - -/* FIXME: -The person who wrote function calls on the SPARC didn't understand the -SPARC stack. There is no need to call into the inferior to run a save -instruction and then do it again for a restore instruction. Save and -restore amount to add-to-SP and move-to-SP when all has been said and -done. You simply modify the stack in memory to look like a function -has been called -- the same way any other architecture does it. - -That would fix the sparc xfail in testsuite/gdb.t06/signals.exp, make -function calls much faster, and would clean up some very poor code. */ - - -/* Neither do_save_insn or do_restore_insn save stack configuration - (current_frame, etc), - since the stack is in an indeterminate state through the call to - each of them. That is the responsibility of the routine which calls them. */ - -static void -do_save_insn (size) - int size; -{ - int g1 = read_register (G1_REGNUM); - CORE_ADDR sp = read_register (SP_REGNUM); - CORE_ADDR pc = read_register (PC_REGNUM); - CORE_ADDR npc = read_register (NPC_REGNUM); - CORE_ADDR fake_pc = sp - sizeof (save_insn_opcodes); - struct inferior_status inf_status; - - save_inferior_status (&inf_status, 0); /* Don't restore stack info */ - /* - * See above. - */ - save_insn_opcodes[0] = 0x03000000 | ((-size >> 10) & 0x3fffff); - save_insn_opcodes[1] = 0x82006000 | (-size & 0x3ff); - save_insn_opcodes[3] = 0x03000000 | ((g1 >> 10) & 0x3fffff); - save_insn_opcodes[4] = 0x82006000 | (g1 & 0x3ff); - write_memory (fake_pc, (char *)save_insn_opcodes, sizeof (save_insn_opcodes)); - - clear_proceed_status (); - stop_after_trap = 1; - proceed (fake_pc, 0, 0); - - write_register (PC_REGNUM, pc); - write_register (NPC_REGNUM, npc); - restore_inferior_status (&inf_status); -} - -/* - * This routine takes a program counter value. It restores the - * register window system to the frame above the current one. - * THIS ROUTINE CLOBBERS PC AND NPC IN THE TARGET! - */ - -/* The following insns translate to: - - restore %g0,%g0,%g0 - t %g0,1 - sethi %hi(0),%g0 */ - -static unsigned int restore_insn_opcodes[] = { - 0x81e80000, 0x91d02001, 0x01000000 }; - -static void -do_restore_insn () -{ - CORE_ADDR sp = read_register (SP_REGNUM); - CORE_ADDR fake_pc = sp - sizeof (restore_insn_opcodes); - struct inferior_status inf_status; - - save_inferior_status (&inf_status, 0); /* Don't restore stack info */ - - write_memory (fake_pc, (char *)restore_insn_opcodes, - sizeof (restore_insn_opcodes)); - - clear_proceed_status (); - stop_after_trap = 1; - proceed (fake_pc, 0, 0); - - restore_inferior_status (&inf_status); -} - /* Given a pc value, skip it forward past the function prologue by disassembling instructions that appear to be a prologue. @@ -545,41 +436,59 @@ sparc_frame_find_saved_regs (fi, saved_regs_addr) /* Push an empty stack frame, and record in it the current PC, regs, etc. - Note that the write's are of registers in the context of the newly - pushed frame. Thus the the fp*'s, the g*'s, the i*'s, and - the randoms, of the new frame, are being saved. The locals and outs + We save the non-windowed registers and the ins. The locals and outs are new; they don't need to be saved. The i's and l's of - the last frame were saved by the do_save_insn in the register - file (now on the stack, since a context switch happended imm after). + the last frame were already saved on the stack - The return pointer register %i7 does not have - the pc saved into it (return from this frame will be accomplished - by a POP_FRAME). In fact, we must leave it unclobbered, since we - must preserve it in the calling routine except across call instructions. */ + The return pointer register %i7 does not have the pc saved into it + (return from this frame will be accomplished by a POP_FRAME). In + fact, we must leave it unclobbered, since we must preserve it in + the calling routine except across call instructions. I'm not sure + the preceding sentence is true; isn't it based on confusing the %i7 + saved in the dummy frame versus the one saved in the frame of the + calling routine? */ /* Definitely see tm-sparc.h for more doc of the frame format here. */ void sparc_push_dummy_frame () { - CORE_ADDR fp; + CORE_ADDR sp; char register_temp[REGISTER_BYTES]; - do_save_insn (0x140); /* FIXME where does this value come from? */ - fp = read_register (FP_REGNUM); + sp = read_register (SP_REGNUM); - read_register_bytes (REGISTER_BYTE (FP0_REGNUM), register_temp, 32 * 4); - write_memory (fp - 0x80, register_temp, 32 * 4); + read_register_bytes (REGISTER_BYTE (FP0_REGNUM), register_temp, + REGISTER_RAW_SIZE (FP0_REGNUM) * 32); + write_memory (sp - 0x80, register_temp, REGISTER_RAW_SIZE (FP0_REGNUM) * 32); - read_register_bytes (REGISTER_BYTE (G0_REGNUM), register_temp, 8 * 4); - write_memory (fp - 0xa0, register_temp, 8 * 4); + read_register_bytes (REGISTER_BYTE (G0_REGNUM), register_temp, + REGISTER_RAW_SIZE (G0_REGNUM) * 8); + write_memory (sp - 0xa0, register_temp, REGISTER_RAW_SIZE (G0_REGNUM) * 8); - read_register_bytes (REGISTER_BYTE (I0_REGNUM), register_temp, 8 * 4); - write_memory (fp - 0xc0, register_temp, 8 * 4); + read_register_bytes (REGISTER_BYTE (O0_REGNUM), register_temp, + REGISTER_RAW_SIZE (O0_REGNUM) * 8); + write_memory (sp - 0xc0, register_temp, REGISTER_RAW_SIZE (O0_REGNUM) * 8); /* Y, PS, WIM, TBR, PC, NPC, FPS, CPS regs */ - read_register_bytes (REGISTER_BYTE (Y_REGNUM), register_temp, 8 * 4); - write_memory (fp - 0xe0, register_temp, 8 * 4); + read_register_bytes (REGISTER_BYTE (Y_REGNUM), register_temp, + REGISTER_RAW_SIZE (Y_REGNUM) * 8); + write_memory (sp - 0xe0, register_temp, REGISTER_RAW_SIZE (Y_REGNUM) * 8); + + { + CORE_ADDR old_sp = sp; + + /* Now move the stack pointer (equivalent to the add part of a save + instruction). */ + sp -= 0x140; + write_register (SP_REGNUM, sp); + + /* Now make sure that the frame pointer we save in the new frame points + to the old frame (equivalent to the register window shift part of + a save instruction). Need to do this after the write to the sp, or + else this might get written into the wrong set of saved ins&locals. */ + write_register (FP_REGNUM, old_sp); + } } /* Discard from the stack the innermost frame, restoring all saved registers. @@ -607,7 +516,6 @@ sparc_pop_frame () fi = get_frame_info (frame); get_frame_saved_regs (fi, &fsr); - do_restore_insn (); if (fsr.regs[FP0_REGNUM]) { read_memory (fsr.regs[FP0_REGNUM], raw_buffer, 32 * 4); @@ -620,8 +528,27 @@ sparc_pop_frame () } if (fsr.regs[I0_REGNUM]) { + CORE_ADDR sp; + + char reg_temp[REGISTER_BYTES]; + read_memory (fsr.regs[I0_REGNUM], raw_buffer, 8 * 4); - write_register_bytes (REGISTER_BYTE (O0_REGNUM), raw_buffer, 8 * 4); + + /* Get the ins and locals which we are about to restore. Just + moving the stack pointer is all that is really needed, except + store_inferior_registers is then going to write the ins and + locals from the registers array, so we need to muck with the + registers array. */ + sp = fsr.regs[SP_REGNUM]; + read_memory (sp, reg_temp, REGISTER_RAW_SIZE (L0_REGNUM) * 16); + + /* Restore the out registers. + Among other things this writes the new stack pointer. */ + write_register_bytes (REGISTER_BYTE (O0_REGNUM), raw_buffer, + REGISTER_RAW_SIZE (O0_REGNUM) * 8); + + write_register_bytes (REGISTER_BYTE (L0_REGNUM), reg_temp, + REGISTER_RAW_SIZE (L0_REGNUM) * 16); } if (fsr.regs[PS_REGNUM]) write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4)); -- 2.34.1