[2/2,RISC-V] resolve confilct between zcmp multi push/pop and shrink-wrap-separate
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Commit Message
Disable zcmp multi push/pop if shrink-wrap-separate is active.
So in -Os that prefers smaller code size, by default shrink-wrap-separate
is disabled while zcmp multi push/pop is enabled.
And in -O2 and others that prefers speed, by default shrink-wrap-separate
is enabled while zcmp multi push/pop is disabled. To force enabling zcmp multi
push/pop in this case, -fno-shrink-wrap-separate has to be explictly given.
The following TC shows the issues in -O2 before this patch with both
shrink-wrap-separate and zcmp multi push/pop active.
1. duplicated store of s regs.
2. cm.push pushes ra, s0-s11 in reverse order than what normal
prologue does, causing stack corruption and failure to resotre s regs.
TC: zcmp_shrink_wrap_separate.c included in this patch.
output asm before this patch:
calc_func:
cm.push {ra, s0-s3}, -32
...
beq a5,zero,.L2
...
.L2:
...
sw s1,20(sp) //issue here
sw s3,12(sp) //issue here
...
sw s2,16(sp) //issue here
output asm after this patch:
calc_func:
addi sp,sp,-32
sw s0,24(sp)
...
beq a5,zero,.L2
...
.L2:
...
sw s1,20(sp)
sw s3,12(sp)
...
sw s2,16(sp)
Signed-off-by: Fei Gao <gaofei@eswincomputing.com>
Co-Authored-By: Zhangjin Liao <liaozhangjin@eswincomputing.com>
gcc/ChangeLog:
* config/riscv/riscv.cc
(riscv_avoid_shrink_wrapping_separate): wrap the condition check in
riscv_avoid_shrink_wrapping_separate.
(riscv_avoid_multi_push): avoid multi push if shrink_wrapping_separate
is active.
(riscv_get_separate_components): call riscv_avoid_shrink_wrapping_separate
---
gcc/config/riscv/riscv.cc | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
@@ -64,6 +64,7 @@ along with GCC; see the file COPYING3. If not see
#include "cfghooks.h"
#include "cfgloop.h"
#include "cfgrtl.h"
+#include "shrink-wrap.h"
#include "sel-sched.h"
#include "fold-const.h"
#include "gimple-iterator.h"
@@ -389,6 +390,7 @@ static const struct riscv_tune_param optimize_size_tune_info = {
false, /* use_divmod_expansion */
};
+static bool riscv_avoid_shrink_wrapping_separate ();
static tree riscv_handle_fndecl_attribute (tree *, tree, tree, int, bool *);
static tree riscv_handle_type_attribute (tree *, tree, tree, int, bool *);
@@ -5032,6 +5034,8 @@ riscv_avoid_multi_push(const struct riscv_frame_info *frame)
|| cfun->machine->interrupt_handler_p
|| cfun->machine->varargs_size != 0
|| crtl->args.pretend_args_size != 0
+ || (use_shrink_wrapping_separate ()
+ && !riscv_avoid_shrink_wrapping_separate ())
|| (frame->mask & ~ MULTI_PUSH_GPR_MASK))
return true;
@@ -6199,6 +6203,17 @@ riscv_epilogue_uses (unsigned int regno)
return false;
}
+static bool
+riscv_avoid_shrink_wrapping_separate ()
+{
+ if (riscv_use_save_libcall (&cfun->machine->frame)
+ || cfun->machine->interrupt_handler_p
+ || !cfun->machine->frame.gp_sp_offset.is_constant ())
+ return true;
+
+ return false;
+}
+
/* Implement TARGET_SHRINK_WRAP_GET_SEPARATE_COMPONENTS. */
static sbitmap
@@ -6208,9 +6223,7 @@ riscv_get_separate_components (void)
sbitmap components = sbitmap_alloc (FIRST_PSEUDO_REGISTER);
bitmap_clear (components);
- if (riscv_use_save_libcall (&cfun->machine->frame)
- || cfun->machine->interrupt_handler_p
- || !cfun->machine->frame.gp_sp_offset.is_constant ())
+ if (riscv_avoid_shrink_wrapping_separate ())
return components;
offset = cfun->machine->frame.gp_sp_offset.to_constant ();