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[spu] Fix single-stepping regression
- From: "Ulrich Weigand" <uweigand at de dot ibm dot com>
- To: gdb-patches at sourceware dot org
- Date: Sun, 26 Nov 2017 17:24:40 +0100 (CET)
- Subject: [spu] Fix single-stepping regression
- Authentication-results: sourceware.org; auth=none
Hello,
switching spu_software_single_step to use a regcache instead of a frame:
https://sourceware.org/ml/gdb-patches/2016-11/msg00355.html
caused a serious regression to SPU single-stepping.
There were two separate problems:
- SPU_LSLR_REGNUM is a pseudo register, so we must use the "cooked"
regcache methods instead of the "raw" ones to access it.
- When accessing a branch target register, we must only use the first
four bytes of the 16-byte vector register. This was done automatically
by the frame routines, but not by the regcache routines.
Bye,
Ulrich
gdb/ChangeLog:
2017-11-26 Ulrich Weigand <uweigand@de.ibm.com>
* spu-tdep.c (spu_software_single_step): Access SPU_LSLR_REGNUM as
"cooked" register. Access only first four bytes of branch target
registers.
diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index ecdc7fc..34a536a 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -1632,8 +1632,8 @@ spu_software_single_step (struct regcache *regcache)
insn = extract_unsigned_integer (buf, 4, byte_order);
/* Get local store limit. */
- lslr = regcache_raw_get_unsigned (regcache, SPU_LSLR_REGNUM);
- if (!lslr)
+ if ((regcache_cooked_read_unsigned (regcache, SPU_LSLR_REGNUM, &lslr)
+ != REG_VALID) || !lslr)
lslr = (ULONGEST) -1;
/* Next sequential instruction is at PC + 4, except if the current
@@ -1653,7 +1653,10 @@ spu_software_single_step (struct regcache *regcache)
if (reg == SPU_PC_REGNUM)
target += SPUADDR_ADDR (pc);
else if (reg != -1)
- target += regcache_raw_get_unsigned (regcache, reg) & -4;
+ {
+ regcache_raw_read_part (regcache, reg, 0, 4, buf);
+ target += extract_unsigned_integer (buf, 4, byte_order) & -4;
+ }
target = target & lslr;
if (target != next_pc)
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com