On Thu, Dec 19, 2019 at 04:50:40PM +0100, Jan Hubicka wrote:
> Outputting the move as RIP relative movq would work.
> LC12 is string "s" and has nothing to do with stack protecting.
This should fix it by doing more carefully what *movdi_internal
does. Will bootstrap/regtest it tonight.
2019-12-19 Jakub Jelinek <ja...@redhat.com>
PR target/92841
* config/i386/i386.md (*stack_protect_set_3): For pic_32bit_operand
always use lea{q}, no matter what value which_alternative has.
* gcc.target/i386/pr92841-2.c: New test.
--- gcc/config/i386/i386.md.jj 2019-12-19 13:31:52.424108730 +0100
+++ gcc/config/i386/i386.md 2019-12-19 18:12:54.064747056 +0100
@@ -19863,12 +19863,13 @@ (define_insn "*stack_protect_set_3"
{
output_asm_insn ("mov{q}\t{%3, %1|%1, %3}", operands);
output_asm_insn ("mov{q}\t{%1, %0|%0, %1}", operands);
- if (which_alternative == 0)
+ if (pic_32bit_operand (operands[2], DImode))
+ return "lea{q}\t{%E2, %1|%1, %E2}";
+ else if (which_alternative == 0)
return "mov{l}\t{%k2, %k1|%k1, %k2}";
else if (which_alternative == 2)
return "movabs{q}\t{%2, %1|%1, %2}";
- else if (pic_32bit_operand (operands[2], DImode)
- || ix86_use_lea_for_mov (insn, operands + 1))
+ else if (ix86_use_lea_for_mov (insn, operands + 1))
return "lea{q}\t{%E2, %1|%1, %E2}";
else
return "mov{q}\t{%2, %1|%1, %2}";
--- gcc/testsuite/gcc.target/i386/pr92841-2.c.jj 2019-12-19
18:18:31.295587557 +0100
+++ gcc/testsuite/gcc.target/i386/pr92841-2.c 2019-12-19 18:19:37.800570175
+0100
@@ -0,0 +1,18 @@
+/* PR target/92841 */
+/* { dg-do compile { target { { { *-*-linux* } && lp64 } && fstack_protector }
} } */
+/* { dg-options "-O2 -fpic -fstack-protector-strong -masm=att" } */
+/* { dg-final { scan-assembler "leaq\tbuf2\\\(%rip\\\)," } } */
+
+static char buf2[64];
+void bar (char *, char *);
+
+void
+foo ()
+{
+ char buf[64];
+ char *p = buf2;
+ asm ("" : "+a" (p));
+ char *q = buf;
+ asm ("" : "+r" (q));
+ bar (p, q);
+}
Jakub
