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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-09-10 12:48:24 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-09-10 17:17:09 -0700 |
| commit | 369ab33a8c08ecc87b762cade267b7b05b1e2551 (patch) | |
| tree | 5ab279aa9a46e5062408053cec30ff91f9fefc22 | |
| parent | 6e17101cbcb91a51a05e29eb0efc5d3b60d8c547 (diff) | |
| download | gcc-hjl/pr82166/master.tar.gz | |
i386: Update preferred stack boundary for leaf functionshjl/pr82166/master
preferred_stack_boundary may not be the minimum stack alignment. For
leaf functions without TLS access, max_used_stack_slot_alignment may be
smaller. We should update preferred_stack_boundary for leaf functions.
gcc/
PR target/82166
* config/i386/i386.c (ix86_finalize_stack_frame_flags): Properly
compute the minimum stack alignment. Also update preferred stack
boundary when main () is a leaf function.
gcc/testsuite/
PR target/82166
* gcc.target/i386/pr82166.c: New test.
| -rw-r--r-- | gcc/config/i386/i386.c | 17 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/i386/pr82166.c | 14 |
2 files changed, 26 insertions, 5 deletions
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 4e93cc1043b..03338e422be 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -14257,11 +14257,12 @@ ix86_finalize_stack_frame_flags (void) unsigned int incoming_stack_boundary = (crtl->parm_stack_boundary > ix86_incoming_stack_boundary ? crtl->parm_stack_boundary : ix86_incoming_stack_boundary); + unsigned int stack_alignment + = (crtl->is_leaf && !ix86_current_function_calls_tls_descriptor + ? crtl->max_used_stack_slot_alignment + : crtl->stack_alignment_needed); unsigned int stack_realign - = (incoming_stack_boundary - < (crtl->is_leaf && !ix86_current_function_calls_tls_descriptor - ? crtl->max_used_stack_slot_alignment - : crtl->stack_alignment_needed)); + = (incoming_stack_boundary < stack_alignment); bool recompute_frame_layout_p = false; if (crtl->stack_realign_finalized) @@ -14306,7 +14307,9 @@ ix86_finalize_stack_frame_flags (void) HARD_FRAME_POINTER_REGNUM); /* The preferred stack alignment is the minimum stack alignment. */ - unsigned int stack_alignment = crtl->preferred_stack_boundary; + if (stack_alignment > crtl->preferred_stack_boundary) + stack_alignment = crtl->preferred_stack_boundary; + bool require_stack_frame = false; FOR_EACH_BB_FN (bb, cfun) @@ -14349,6 +14352,10 @@ ix86_finalize_stack_frame_flags (void) = incoming_stack_boundary; crtl->stack_alignment_needed = incoming_stack_boundary; + /* Also update preferred_stack_boundary for leaf + functions. */ + crtl->preferred_stack_boundary + = incoming_stack_boundary; } } else diff --git a/gcc/testsuite/gcc.target/i386/pr82166.c b/gcc/testsuite/gcc.target/i386/pr82166.c new file mode 100644 index 00000000000..8bc63e15231 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr82166.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-Os" } */ + +void foo (void); +int a, b, c; +int +main (void) +{ + int j; + for (; c;) + a = b; + for (; j;) + foo (); +} |