"H.J. Lu" <hjl.to...@gmail.com> writes:
> 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?
Sorry for the delay. I was testing this in parallel.
Bootstrapped & regression-tested on x86_64-linux-gnu.
Thanks,
Richard
>From af4499845d26fe65573b21197a79fd22fd38694e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Tue, 15 Sep 2020 06:23:26 -0700
Subject: [PATCH] ira: Fix elimination for global hard FPs [PR91957]
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
If the hard frame pointer is being used as a global register,
we should skip the usual handling for eliminations. As the
comment says, the register cannot in that case be eliminated
(or eliminated to) and is already marked live where appropriate.
Doing this removes the duplicate error for gcc.target/i386/pr82673.c.
The “cannot be used in 'asm' here” message is meant to be for asm
statements rather than register asms, and the function that the
error is reported against doesn't use asm.
gcc/
2020-09-16 Richard Sandiford <richard.sandif...@arm.com>
PR middle-end/91957
* ira.c (ira_setup_eliminable_regset): Skip the special elimination
handling of the hard frame pointer if the hard frame pointer is fixed.
gcc/testsuite/
2020-09-16 H.J. Lu <hjl.to...@gmail.com>
Richard Sandiford <richard.sandif...@arm.com>
PR middle-end/91957
* g++.target/i386/pr97054.C: New test.
* gcc.target/i386/pr82673.c: Remove redundant extra message.
---
gcc/ira.c | 8 ++-
gcc/testsuite/g++.target/i386/pr97054.C | 96 +++++++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr82673.c | 2 +-
3 files changed, 103 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.target/i386/pr97054.C
diff --git a/gcc/ira.c b/gcc/ira.c
index a759f3c2aa8..27d1b3c857d 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -2310,8 +2310,12 @@ ira_setup_eliminable_regset (void)
if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
{
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])
+ /* Nothing to do: the register is already treated as live
+ where appropriate, and cannot be eliminated. */
+ ;
+ else if (!TEST_HARD_REG_BIT (crtl->asm_clobbers,
+ HARD_FRAME_POINTER_REGNUM + i))
{
SET_HARD_REG_BIT (eliminable_regset,
HARD_FRAME_POINTER_REGNUM + i);
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;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr82673.c
b/gcc/testsuite/gcc.target/i386/pr82673.c
index 161ec88e3a7..2248295a087 100644
--- a/gcc/testsuite/gcc.target/i386/pr82673.c
+++ b/gcc/testsuite/gcc.target/i386/pr82673.c
@@ -9,4 +9,4 @@ void
bar (void) /* { dg-error "frame pointer required, but reserved" } */
{
B = &y;
-} /* { dg-error "bp cannot be used in 'asm' here" } */
+}
--
2.17.1
