On Tue, Sep 15, 2020 at 7:44 AM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> Thanks for looking at this.
>
> "H.J. Lu" <hjl.to...@gmail.com> writes:
> > commit 1bcb4c4faa4bd6b1c917c75b100d618faf9e628c
> > Author: Richard Sandiford <richard.sandif...@arm.com>
> > Date: Wed Oct 2 07:37:10 2019 +0000
> >
> > [LRA] Don't make eliminable registers live (PR91957)
> >
> > didn't make eliminable registers live which breaks
> >
> > register void *cur_pro asm("reg");
> >
> > where "reg" is an eliminable register. Make fixed eliminable registers
> > live to fix it.
>
> I don't think fixedness itself is the issue here: it's usual for at
> least some registers involved in eliminations to be fixed registers.
>
> I think what makes this case different is instead that cur_pro/ebp
> is a global register. But IMO things have already gone wrong if we
> think that a global register is eliminable.
>
> So I wonder if instead we should check global_regs at the beginning of:
>
> for (i = 0; i < fp_reg_count; i++)
> if (!TEST_HARD_REG_BIT (crtl->asm_clobbers,
> HARD_FRAME_POINTER_REGNUM + i))
> {
> SET_HARD_REG_BIT (eliminable_regset,
> HARD_FRAME_POINTER_REGNUM + i);
> if (frame_pointer_needed)
> SET_HARD_REG_BIT (ira_no_alloc_regs,
> HARD_FRAME_POINTER_REGNUM + i);
> }
> else if (frame_pointer_needed)
> error ("%s cannot be used in %<asm%> here",
> reg_names[HARD_FRAME_POINTER_REGNUM + i]);
> else
> df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM + i, true);
>
> (ira_setup_eliminable_regset), and handle the global_regs[] case in
> the same way as the else case, i.e. short-circuiting both of the ifs.
>
Like this?
Thanks.
--
H.J.
From d1c852691d245d90666c1b977775fc7f8db2b241 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Tue, 15 Sep 2020 04:17:54 -0700
Subject: [PATCH] IRA: Don't make a global register eliminable
commit 1bcb4c4faa4bd6b1c917c75b100d618faf9e628c
Author: Richard Sandiford <richard.sandif...@arm.com>
Date: Wed Oct 2 07:37:10 2019 +0000
[LRA] Don't make eliminable registers live (PR91957)
didn't make eliminable registers live which breaks
register void *cur_pro asm("reg");
where "reg" is an eliminable register. Update ira_setup_eliminable_regset
to avoid making global registers eliminable.
gcc/
PR middle-end/97054
* ira.c (ira_setup_eliminable_regset): Don't make a global
register eliminable.
gcc/testsuite/
PR middle-end/97054
* g++.target/i386/pr97054.C: New test.
---
gcc/ira.c | 30 ++++----
gcc/testsuite/g++.target/i386/pr97054.C | 96 +++++++++++++++++++++++++
2 files changed, 114 insertions(+), 12 deletions(-)
create mode 100644 gcc/testsuite/g++.target/i386/pr97054.C
diff --git a/gcc/ira.c b/gcc/ira.c
index a759f3c2aa8..506c6e6783e 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -2309,21 +2309,27 @@ ira_setup_eliminable_regset (void)
}
if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
{
+ /* NB: Don't make a global register eliminable. */
for (i = 0; i < fp_reg_count; i++)
- if (!TEST_HARD_REG_BIT (crtl->asm_clobbers,
- HARD_FRAME_POINTER_REGNUM + i))
+ if (global_regs[HARD_FRAME_POINTER_REGNUM + i])
+ df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM + i, true);
+ else
{
- SET_HARD_REG_BIT (eliminable_regset,
- HARD_FRAME_POINTER_REGNUM + i);
- if (frame_pointer_needed)
- SET_HARD_REG_BIT (ira_no_alloc_regs,
- HARD_FRAME_POINTER_REGNUM + i);
+ if (!TEST_HARD_REG_BIT (crtl->asm_clobbers,
+ HARD_FRAME_POINTER_REGNUM + i))
+ {
+ SET_HARD_REG_BIT (eliminable_regset,
+ HARD_FRAME_POINTER_REGNUM + i);
+ if (frame_pointer_needed)
+ SET_HARD_REG_BIT (ira_no_alloc_regs,
+ HARD_FRAME_POINTER_REGNUM + i);
+ }
+ else if (frame_pointer_needed)
+ error ("%s cannot be used in %<asm%> here",
+ reg_names[HARD_FRAME_POINTER_REGNUM + i]);
+ else
+ df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM + i, true);
}
- else if (frame_pointer_needed)
- error ("%s cannot be used in %<asm%> here",
- reg_names[HARD_FRAME_POINTER_REGNUM + i]);
- else
- df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM + i, true);
}
}
diff --git a/gcc/testsuite/g++.target/i386/pr97054.C b/gcc/testsuite/g++.target/i386/pr97054.C
new file mode 100644
index 00000000000..d0693af2a42
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/pr97054.C
@@ -0,0 +1,96 @@
+// { dg-do run { target { ! ia32 } } }
+// { dg-require-effective-target fstack_protector }
+// { dg-options "-O2 -fno-strict-aliasing -msse4.2 -mfpmath=sse -fPIC -fstack-protector-strong -O2" }
+
+struct p2_icode *ipc;
+register int pars asm("r13");
+register struct processor *cur_pro asm("rbp");
+register int a asm("rbx");
+register int c asm("r14");
+typedef long lina_t;
+typedef long la_t;
+typedef processor processor_t;
+typedef p2_icode p2_icode_t;
+typedef enum {
+ P2_Return_Action_Next,
+} p2_return_action_t;
+typedef struct p2_icode {
+ int ic_Parameters;
+} icode_t;
+extern "C" icode_t *x86_log_to_icode_exec(processor_t *, la_t);
+typedef struct {
+ icode_t *ipc;
+} b;
+typedef struct {
+ char ma_thread_signal;
+ int event_counter;
+ b instrumentation;
+} d;
+
+extern "C" lina_t int2linaddr(processor_t *cpu, const p2_icode_t *ic)
+{
+ return 0;
+}
+
+typedef struct e {
+ long i64;
+ char LMA;
+} f;
+
+struct processor {
+ d common;
+ e pc_RIP;
+ f pc_EFER;
+ p2_icode_t *saved_ipc;
+};
+inline la_t code_lin_to_log(processor_t *, long) { return 0; }
+void turbo_clear(processor_t *) {}
+
+p2_return_action_t p2_ep_REBIND_IPC(void)
+{
+ processor_t *cpu = cur_pro;
+ la_t vaddr = cpu->pc_RIP.i64;
+ cur_pro->saved_ipc = (p2_icode_t *) ipc;
+ cur_pro->common.instrumentation.ipc = ipc;
+ cur_pro->pc_RIP.i64 = code_lin_to_log(cur_pro, int2linaddr(cur_pro, ipc));
+ turbo_clear(cur_pro);
+
+ cpu->saved_ipc = x86_log_to_icode_exec(cur_pro, vaddr);
+ ipc++;
+ (cur_pro->common.event_counter -= (1));
+ if (__builtin_expect((!((cur_pro->common.event_counter <= 0)
+ | cur_pro->common.ma_thread_signal)), 1))
+ {
+ ((pars = ((ipc)->ic_Parameters)));
+ return P2_Return_Action_Next;
+ } else {
+ return (p2_return_action_t) 0;
+ }
+ return P2_Return_Action_Next;
+}
+
+struct p2_icode fake_ipc = { 0 };
+struct processor fake_proc ={{ 0 } };
+
+extern "C" icode_t *
+x86_log_to_icode_exec(processor_t *cpu, la_t la)
+{
+ return 0;
+}
+
+extern "C" void
+turbo_threshold_reached(processor_t *c, p2_icode_t *i, int s)
+{
+}
+
+int main()
+{
+ if (!__builtin_cpu_supports ("sse4.2"))
+ return 0;
+ fake_proc.pc_RIP.i64 = 0xbaadc0de;
+ fake_proc.pc_EFER.LMA = 0xf;
+ ipc = &fake_ipc;
+ cur_pro = &fake_proc;
+ p2_ep_REBIND_IPC();
+ return 0;
+}
--
2.26.2
