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[PATCH] i386: Replace frame pointer with stack pointer in debug insns
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Uros Bizjak <ubizjak at gmail dot com>
- Date: Fri, 11 Aug 2017 18:32:28 -0700
- Subject: [PATCH] i386: Replace frame pointer with stack pointer in debug insns
- Authentication-results: sourceware.org; auth=none
When we eliminate frame pointer, we should also replace frame pointer
with stack pointer - UNITS_PER_WORD in debug insns. This patch fixed:
FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b1 == 9
FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b2 == 73
FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b3 == 585
FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b4 == 4681
FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:17 s1.f == 5.0
FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:17 s1.g == 6.0
FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:17 s2.g == 6.0
FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s1.f == 5.0
FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s1.g == 6.0
FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s2.f == 5.0
FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s2.g == 6.0
on Linux/i386.
Tested on i686 and x86-64. OK for trunk?
H.J.
---
PR target/81820
* config/i386/i386.c (ix86_finalize_stack_frame_flags): Replace
frame pointer with stack pointer - UNITS_PER_WORD in debug insns.
---
gcc/config/i386/i386.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index b04321a8d40..0094f2c4441 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -14281,6 +14281,42 @@ ix86_finalize_stack_frame_flags (void)
df_scan_blocks ();
df_compute_regs_ever_live (true);
df_analyze ();
+
+ if (flag_var_tracking)
+ {
+ /* Since frame pointer is no longer needed, replace it with
+ stack pointer - UNITS_PER_WORD in debug insns. */
+ df_ref ref, next;
+ for (ref = DF_REG_USE_CHAIN (HARD_FRAME_POINTER_REGNUM);
+ ref; ref = next)
+ {
+ rtx_insn *insn = DF_REF_INSN (ref);
+ /* Make sure the next ref is for a different instruction,
+ so that we're not affected by the rescan. */
+ next = DF_REF_NEXT_REG (ref);
+ while (next && DF_REF_INSN (next) == insn)
+ next = DF_REF_NEXT_REG (next);
+
+ if (DEBUG_INSN_P (insn))
+ {
+ bool changed = false;
+ for (; ref != next; ref = DF_REF_NEXT_REG (ref))
+ {
+ rtx *loc = DF_REF_LOC (ref);
+ if (*loc == hard_frame_pointer_rtx)
+ {
+ *loc = plus_constant (Pmode,
+ stack_pointer_rtx,
+ -UNITS_PER_WORD);
+ changed = true;
+ }
+ }
+ if (changed)
+ df_insn_rescan (insn);
+ }
+ }
+ }
+
recompute_frame_layout_p = true;
}
--
2.13.4