Re: [PATCH, i386]: Fix PR target/48723
What is wrong? x86-64 has 128byte redzone. Nothing wrong, just strange. ISTM that it doesn't serve any useful purpose. And I'm not sure that the rest of the code in ix86_expand_prologue is really prepared for a negative size either. -- Eric Botcazou
Re: [PATCH, i386]: Fix PR target/48723
On Saturday 23 April 2011 09:35:38 Uros Bizjak wrote:
Index: i386.c
===
--- i386.c(revision 172866)
+++ i386.c(working copy)
@@ -10149,7 +10149,7 @@ ix86_adjust_stack_and_probe (const HOST_
/* Even if the stack pointer isn't the CFA register, we need to
correctly describe the adjustments made to it, in particular differentiate
the frame-related ones from the frame-unrelated ones. */
- if (size 0)
+ if (size != 0)
{
rtx expr = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (2));
XVECEXP (expr, 0, 0)
Probing for a negative size doesn't make much sense; we shouldn't be there if
the size to allocate is negative. Is that really intended? The code without
stack checking is:
pushq %rbp
.LCFI0:
movq%rsp, %rbp
.LCFI1:
andq$-32, %rsp
addq$16, %rsp
which looks weird. If this is nevertheless correct, then the fix for the
problem is attached. Tested on x86_64-suse-linux.
PR target/48723
* config/i386/i386.c (ix86_expand_prologue): Do not probe the stack
for -fstack-check if the size to allocate is negative.
--
Eric Botcazou
Index: config/i386/i386.c
===
--- config/i386/i386.c (revision 173209)
+++ config/i386/i386.c (working copy)
@@ -10619,8 +10619,8 @@ ix86_expand_prologue (void)
}
/* The stack has already been decremented by the instruction calling us
- so we need to probe unconditionally to preserve the protection area. */
- if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
+ so probe if the size is non-negative to preserve the protection area. */
+ if (allocate = 0 flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
{
/* We expect the registers to be saved when probes are used. */
gcc_assert (int_registers_saved);
Re: [PATCH, i386]: Fix PR target/48723
On Sat, Apr 30, 2011 at 1:55 PM, Eric Botcazou ebotca...@adacore.com wrote:
On Saturday 23 April 2011 09:35:38 Uros Bizjak wrote:
Index: i386.c
===
--- i386.c (revision 172866)
+++ i386.c (working copy)
@@ -10149,7 +10149,7 @@ ix86_adjust_stack_and_probe (const HOST_
/* Even if the stack pointer isn't the CFA register, we need to
correctly describe the adjustments made to it, in particular differentiate
the frame-related ones from the frame-unrelated ones. */
- if (size 0)
+ if (size != 0)
{
rtx expr = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (2));
XVECEXP (expr, 0, 0)
Probing for a negative size doesn't make much sense; we shouldn't be there if
the size to allocate is negative. Is that really intended? The code without
stack checking is:
pushq %rbp
.LCFI0:
movq %rsp, %rbp
.LCFI1:
andq $-32, %rsp
addq $16, %rsp
which looks weird. If this is nevertheless correct, then the fix for the
problem is attached. Tested on x86_64-suse-linux.
This code aligns stack to 32byte for AVX.
--
H.J.
Re: [PATCH, i386]: Fix PR target/48723
This code aligns stack to 32byte for AVX. Right, the strange line is the next one. -- Eric Botcazou
Re: [PATCH, i386]: Fix PR target/48723
On Sat, Apr 30, 2011 at 2:56 PM, Eric Botcazou ebotca...@adacore.com wrote: This code aligns stack to 32byte for AVX. Right, the strange line is the next one. What is wrong? x86-64 has 128byte redzone. -- H.J.
Re: [PATCH, i386]: Fix PR target/48723
On Fri, Apr 22, 2011 at 11:38 PM, Eric Botcazou ebotca...@adacore.com wrote:
Attached one-liner fixes PR target/48723, ICE in
ix86_expand_prologue() with -fstack-check + function returning struct,
on corei7-avx. The problem was, that we forgot to update accounting
info when ix86_adjust_stack_and_probe adjusted stack pointer (in this
particular case, m-fs.sp_offset was set by stack realignment code for
AVX 32byte stack alignment.
Take a look at line 10165 of config/i386/i386.c.
Index: i386.c
===
--- i386.c (revision 172866)
+++ i386.c (working copy)
@@ -10149,7 +10149,7 @@ ix86_adjust_stack_and_probe (const HOST_
/* Even if the stack pointer isn't the CFA register, we need to correctly
describe the adjustments made to it, in particular differentiate the
frame-related ones from the frame-unrelated ones. */
- if (size 0)
+ if (size != 0)
{
rtx expr = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (2));
XVECEXP (expr, 0, 0)
Uros.
Re: [PATCH, i386]: Fix PR target/48723
On Fri, Apr 22, 2011 at 11:38 PM, Eric Botcazou ebotca...@adacore.com wrote: Attached one-liner fixes PR target/48723, ICE in ix86_expand_prologue() with -fstack-check + function returning struct, on corei7-avx. The problem was, that we forgot to update accounting info when ix86_adjust_stack_and_probe adjusted stack pointer (in this particular case, m-fs.sp_offset was set by stack realignment code for AVX 32byte stack alignment. Take a look at line 10165 of config/i386/i386.c. I have reverted my original patch. Uros.
