This patch fixes PR63596.
There is no need to push/pop all arguments registers. We only need to
push and pop those registers used. These use info is calculated by a
dedicated vaarg optimization tree pass "tree-stdarg", the backend should
honor it's analysis result.
For a simple testcase where vaarg declared but actually not used:
int
f (int a, ...)
{
return a;
}
before this patch, we are generating:
f:
sub sp, sp, #192
stp x1, x2, [sp, 136]
stp x3, x4, [sp, 152]
stp x5, x6, [sp, 168]
str x7, [sp, 184]
str q0, [sp]
str q1, [sp, 16]
str q2, [sp, 32]
str q3, [sp, 48]
str q4, [sp, 64]
str q5, [sp, 80]
str q6, [sp, 96]
str q7, [sp, 112]
add sp, sp, 192
ret
after this patch, it's optimized into:
f:
ret
OK for trunk?
2016-05-06 Jiong Wang <jiong.w...@arm.com>
gcc/
PR63596
* config/aarch64/aarch64.c (aarch64_expand_builtin_va_start): Honor
tree-stdarg analysis results.
(aarch64_setup_incoming_varargs): Likewise.
gcc/testsuite/
PR63596
* gcc.target/aarch64/va_arg_1.c: New testcase.
* gcc.target/aarch64/va_arg_2.c: Likewise.
* gcc.target/aarch64/va_arg_3.c: Likewise.
>From dfcfe78511047501ed4b2f323b190c1290314104 Mon Sep 17 00:00:00 2001
From: "Jiong.Wang" <jiong.w...@arm.com>
Date: Fri, 6 May 2016 14:36:42 +0100
Subject: [PATCH 2/4] 2
---
gcc/config/aarch64/aarch64.c | 35 ++++++++++++++++++-----------
gcc/testsuite/gcc.target/aarch64/va_arg_1.c | 11 +++++++++
gcc/testsuite/gcc.target/aarch64/va_arg_2.c | 18 +++++++++++++++
gcc/testsuite/gcc.target/aarch64/va_arg_3.c | 26 +++++++++++++++++++++
4 files changed, 77 insertions(+), 13 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/aarch64/va_arg_1.c
create mode 100644 gcc/testsuite/gcc.target/aarch64/va_arg_2.c
create mode 100644 gcc/testsuite/gcc.target/aarch64/va_arg_3.c
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index aff4a95..b1a0287 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -9502,15 +9502,17 @@ aarch64_expand_builtin_va_start (tree valist, rtx nextarg ATTRIBUTE_UNUSED)
tree f_stack, f_grtop, f_vrtop, f_groff, f_vroff;
tree stack, grtop, vrtop, groff, vroff;
tree t;
- int gr_save_area_size;
- int vr_save_area_size;
+ int gr_save_area_size = cfun->va_list_gpr_size;
+ int vr_save_area_size = cfun->va_list_fpr_size;
int vr_offset;
cum = &crtl->args.info;
- gr_save_area_size
- = (NUM_ARG_REGS - cum->aapcs_ncrn) * UNITS_PER_WORD;
- vr_save_area_size
- = (NUM_FP_ARG_REGS - cum->aapcs_nvrn) * UNITS_PER_VREG;
+ if (cfun->va_list_gpr_size)
+ gr_save_area_size = MIN ((NUM_ARG_REGS - cum->aapcs_ncrn) * UNITS_PER_WORD,
+ cfun->va_list_gpr_size);
+ if (cfun->va_list_fpr_size)
+ vr_save_area_size = MIN ((NUM_FP_ARG_REGS - cum->aapcs_nvrn)
+ * UNITS_PER_VREG, cfun->va_list_fpr_size);
if (!TARGET_FLOAT)
{
@@ -9844,7 +9846,8 @@ aarch64_setup_incoming_varargs (cumulative_args_t cum_v, machine_mode mode,
{
CUMULATIVE_ARGS *cum = get_cumulative_args (cum_v);
CUMULATIVE_ARGS local_cum;
- int gr_saved, vr_saved;
+ int gr_saved = cfun->va_list_gpr_size;
+ int vr_saved = cfun->va_list_fpr_size;
/* The caller has advanced CUM up to, but not beyond, the last named
argument. Advance a local copy of CUM past the last "real" named
@@ -9852,9 +9855,14 @@ aarch64_setup_incoming_varargs (cumulative_args_t cum_v, machine_mode mode,
local_cum = *cum;
aarch64_function_arg_advance (pack_cumulative_args(&local_cum), mode, type, true);
- /* Found out how many registers we need to save. */
- gr_saved = NUM_ARG_REGS - local_cum.aapcs_ncrn;
- vr_saved = NUM_FP_ARG_REGS - local_cum.aapcs_nvrn;
+ /* Found out how many registers we need to save.
+ Honor tree-stdvar analysis results. */
+ if (cfun->va_list_gpr_size)
+ gr_saved = MIN (NUM_ARG_REGS - local_cum.aapcs_ncrn,
+ cfun->va_list_gpr_size / UNITS_PER_WORD);
+ if (cfun->va_list_fpr_size)
+ vr_saved = MIN (NUM_FP_ARG_REGS - local_cum.aapcs_nvrn,
+ cfun->va_list_fpr_size / UNITS_PER_VREG);
if (!TARGET_FLOAT)
{
@@ -9882,7 +9890,7 @@ aarch64_setup_incoming_varargs (cumulative_args_t cum_v, machine_mode mode,
/* We can't use move_block_from_reg, because it will use
the wrong mode, storing D regs only. */
machine_mode mode = TImode;
- int off, i;
+ int off, i, vr_start;
/* Set OFF to the offset from virtual_incoming_args_rtx of
the first vector register. The VR save area lies below
@@ -9891,14 +9899,15 @@ aarch64_setup_incoming_varargs (cumulative_args_t cum_v, machine_mode mode,
STACK_BOUNDARY / BITS_PER_UNIT);
off -= vr_saved * UNITS_PER_VREG;
- for (i = local_cum.aapcs_nvrn; i < NUM_FP_ARG_REGS; ++i)
+ vr_start = V0_REGNUM + local_cum.aapcs_nvrn;
+ for (i = 0; i < vr_saved; ++i)
{
rtx ptr, mem;
ptr = plus_constant (Pmode, virtual_incoming_args_rtx, off);
mem = gen_frame_mem (mode, ptr);
set_mem_alias_set (mem, get_varargs_alias_set ());
- aarch64_emit_move (mem, gen_rtx_REG (mode, V0_REGNUM + i));
+ aarch64_emit_move (mem, gen_rtx_REG (mode, vr_start + i));
off += UNITS_PER_VREG;
}
}
diff --git a/gcc/testsuite/gcc.target/aarch64/va_arg_1.c b/gcc/testsuite/gcc.target/aarch64/va_arg_1.c
new file mode 100644
index 0000000..e8e3cda
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/va_arg_1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 --save-temps" } */
+
+int
+f (int a, ...)
+{
+ /* { dg-final { scan-assembler-not "str" } } */
+ return a;
+}
+
+/* { dg-final { cleanup-saved-temps } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/va_arg_2.c b/gcc/testsuite/gcc.target/aarch64/va_arg_2.c
new file mode 100644
index 0000000..f5c46cb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/va_arg_2.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 --save-temps" } */
+
+int
+foo (char *fmt, ...)
+{
+ int d;
+ __builtin_va_list ap;
+
+ __builtin_va_start (ap, fmt);
+ d = __builtin_va_arg (ap, int);
+ __builtin_va_end (ap);
+
+ /* { dg-final { scan-assembler-not "x7" } } */
+ return d;
+}
+
+/* { dg-final { cleanup-saved-temps } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/va_arg_3.c b/gcc/testsuite/gcc.target/aarch64/va_arg_3.c
new file mode 100644
index 0000000..7f7601a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/va_arg_3.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 --save-temps" } */
+
+int d2i (double a);
+
+int
+foo (char *fmt, ...)
+{
+ int d, e;
+ double f, g;
+ __builtin_va_list ap;
+
+ __builtin_va_start (ap, fmt);
+ d = __builtin_va_arg (ap, int);
+ f = __builtin_va_arg (ap, double);
+ g = __builtin_va_arg (ap, double);
+ d += d2i (f);
+ d += d2i (g);
+ __builtin_va_end (ap);
+
+ /* { dg-final { scan-assembler-not "x7" } } */
+ /* { dg-final { scan-assembler-not "q7" } } */
+ return d;
+}
+
+/* { dg-final { cleanup-saved-temps } } */
--
1.9.1
