From 426a40796aa976355999b2ae401820b9c4a72be9 Mon Sep 17 00:00:00 2001 From: Sandra Loosemore Date: Thu, 6 Nov 2014 12:56:27 -0800 Subject: [PATCH] Update Nios II prologue analysis to remove detection of long-obsolete code sequences. 2014-11-06 Sandra Loosemore gdb/ * nios2-tdep.c (wild_insn): Delete. (profiler_insn, irqentry_insn): Delete. (nios2_match_sequence): Delete. (nios2_analyze_prologue): Update comments. Remove matching of obsolete profiler_insn and irqentry_insn sequences. --- gdb/ChangeLog | 8 ++++ gdb/nios2-tdep.c | 96 +++--------------------------------------------- 2 files changed, 14 insertions(+), 90 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 185d5e899a0..a47cec40e45 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,11 @@ +2014-11-06 Sandra Loosemore + + * nios2-tdep.c (wild_insn): Delete. + (profiler_insn, irqentry_insn): Delete. + (nios2_match_sequence): Delete. + (nios2_analyze_prologue): Update comments. Remove matching + of obsolete profiler_insn and irqentry_insn sequences. + 2014-11-05 Alan Modra * charset.c (convert_between_encodings): Shrink obstack using diff --git a/gdb/nios2-tdep.c b/gdb/nios2-tdep.c index 69cefac638c..1b647ac941b 100644 --- a/gdb/nios2-tdep.c +++ b/gdb/nios2-tdep.c @@ -331,58 +331,6 @@ nios2_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc) return 0; } -/* Define some instruction patterns supporting wildcard bits via a - mask. */ - -typedef struct -{ - unsigned int insn; - unsigned int mask; -} wild_insn; - -static const wild_insn profiler_insn[] = -{ - { 0x0010e03a, 0x00000000 }, /* nextpc r8 */ - { 0xf813883a, 0x00000000 }, /* mov r9,ra */ - { 0x02800034, 0x003fffc0 }, /* movhi r10,257 */ - { 0x52800004, 0x003fffc0 }, /* addi r10,r10,-31992 */ - { 0x00000000, 0xffffffc0 }, /* call */ - { 0x483f883a, 0x00000000 } /* mov ra,r9 */ -}; - -static const wild_insn irqentry_insn[] = -{ - { 0x0031307a, 0x00000000 }, /* rdctl et,estatus */ - { 0xc600004c, 0x00000000 }, /* andi et,et,1 */ - { 0xc0000026, 0x003fffc0 }, /* beq et,zero, */ - { 0x0031313a, 0x00000000 }, /* rdctl et,ipending */ - { 0xc0000026, 0x003fffc0 } /* beq et,zero, */ -}; - - -/* Attempt to match SEQUENCE, which is COUNT insns long, at START_PC. */ - -static int -nios2_match_sequence (struct gdbarch *gdbarch, CORE_ADDR start_pc, - const wild_insn *sequence, int count) -{ - CORE_ADDR pc = start_pc; - int i; - unsigned int insn; - enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); - - for (i = 0 ; i < count ; i++) - { - insn = read_memory_unsigned_integer (pc, NIOS2_OPCODE_SIZE, byte_order); - if ((insn & ~sequence[i].mask) != sequence[i].insn) - return 0; - - pc += NIOS2_OPCODE_SIZE; - } - - return 1; -} - /* Do prologue analysis, returning the PC of the first instruction after the function prologue. Assumes CACHE has already been initialized. THIS_FRAME can be null, in which case we are only @@ -390,30 +338,15 @@ nios2_match_sequence (struct gdbarch *gdbarch, CORE_ADDR start_pc, from the frame information. The prologue will consist of the following parts: - 1) Optional profiling instrumentation. The old version uses six - instructions. We step over this if there is an exact match. - nextpc r8 - mov r9, ra - movhi r10, %hiadj(.LP2) - addi r10, r10, %lo(.LP2) - call mcount - mov ra, r9 - The new version uses two or three instructions (the last of + 1) Optional profiling instrumentation. + This uses two or three instructions (the last of these might get merged in with the STW which saves RA to the stack). We interpret these. mov r8, ra call mcount mov ra, r8 - 2) Optional interrupt entry decision. Again, we step over - this if there is an exact match. - rdctl et,estatus - andi et,et,1 - beq et,zero, - rdctl et,ipending - beq et,zero, - - 3) A stack adjustment or stack which, which will be one of: + 2) A stack adjustment or stack which, which will be one of: addi sp, sp, -constant or: movi r8, constant @@ -428,7 +361,7 @@ nios2_match_sequence (struct gdbarch *gdbarch, CORE_ADDR start_pc, stw sp, constant(rx) mov sp, rx - 4) An optional stack check, which can take either of these forms: + 3) An optional stack check, which can take either of these forms: bgeu sp, rx, +8 break 3 or @@ -437,7 +370,7 @@ nios2_match_sequence (struct gdbarch *gdbarch, CORE_ADDR start_pc, .Lstack_overflow: break 3 - 5) Saving any registers which need to be saved. These will + 4) Saving any registers which need to be saved. These will normally just be stored onto the stack: stw rx, constant(sp) but in the large frame case will use r8 as an offset back @@ -449,7 +382,7 @@ nios2_match_sequence (struct gdbarch *gdbarch, CORE_ADDR start_pc, rdctl rx, ctlN stw rx, constant(sp) - 6) An optional FP setup, either if the user has requested a + 5) An optional FP setup, either if the user has requested a frame pointer or if the function calls alloca. This is always: mov fp, sp @@ -511,23 +444,6 @@ nios2_analyze_prologue (struct gdbarch *gdbarch, const CORE_ADDR start_pc, /* Set up the default values of the registers. */ nios2_setup_default (cache); - - /* If the first few instructions are the profile entry, then skip - over them. Newer versions of the compiler use more efficient - profiling code. */ - if (nios2_match_sequence (gdbarch, pc, profiler_insn, - ARRAY_SIZE (profiler_insn))) - pc += ARRAY_SIZE (profiler_insn) * NIOS2_OPCODE_SIZE; - - /* If the first few instructions are an interrupt entry, then skip - over them too. */ - if (nios2_match_sequence (gdbarch, pc, irqentry_insn, - ARRAY_SIZE (irqentry_insn))) - { - pc += ARRAY_SIZE (irqentry_insn) * NIOS2_OPCODE_SIZE; - exception_handler = 1; - } - prologue_end = start_pc; /* Find the prologue instructions. */ -- 2.39.2