This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Backport the recent ARM ABI patch to 6 (PR target/77728)
- From: "Richard Earnshaw (lists)" <Richard dot Earnshaw at arm dot com>
- To: Marek Polacek <polacek at redhat dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, Jakub Jelinek <jakub at redhat dot com>, Ramana Radhakrishnan <ramana dot radhakrishnan at arm dot com>
- Date: Fri, 5 May 2017 16:29:10 +0100
- Subject: Re: [PATCH] Backport the recent ARM ABI patch to 6 (PR target/77728)
- Authentication-results: sourceware.org; auth=none
- References: <20170427104442.GA4255@redhat.com> <20170504100833.GL4255@redhat.com>
On 04/05/17 11:08, Marek Polacek wrote:
> Ping.
>
> On Thu, Apr 27, 2017 at 12:44:42PM +0200, Marek Polacek wrote:
>> This is a backport of the ARM ABI fix, except that it doesn't change code,
>> only adds the ABI warning.
>>
>> So there were four changes, three of them are changing "else if (res < 0)"
>> to "if (res != 0)" and the fourth was the "res != 0" change in
>> arm_function_arg_boundary.
>>
>> I've verified on a testcase that we now get the warning but there are no
>> changes in .s files.
>>
>> Bootstrapped/regtested on armv7hl-linux-gnueabi, ok for 6?
>>
>> 2017-04-26 Marek Polacek <polacek@redhat.com>
>> Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
>> Jakub Jelinek <jakub@redhat.com>
>>
>> PR target/77728
>> * config/arm/arm.c: Include gimple.h.
>> (aapcs_layout_arg): Emit -Wpsabi note if arm_needs_doubleword_align
>> returns negative, increment ncrn if it returned non-zero.
>> (arm_needs_doubleword_align): Return int instead of bool,
>> ignore DECL_ALIGN of non-FIELD_DECL TYPE_FIELDS chain
>> members, but if there is any such non-FIELD_DECL
>> > PARM_BOUNDARY aligned decl, return -1 instead of false.
>> (arm_function_arg): Emit -Wpsabi note if arm_needs_doubleword_align
>> returns negative, increment nregs if it returned non-zero.
>> (arm_setup_incoming_varargs): Likewise.
>> (arm_function_arg_boundary): Emit -Wpsabi note if
>> arm_needs_doubleword_align returns negative, return
>> DOUBLEWORD_ALIGNMENT if it returned non-zero.
>>
>> * g++.dg/abi/pr77728-1.C: New test.
>>
OK.
R.
>> diff --git gcc/config/arm/arm.c gcc/config/arm/arm.c
>> index 6373103..b3da8c8 100644
>> --- gcc/config/arm/arm.c
>> +++ gcc/config/arm/arm.c
>> @@ -61,6 +61,7 @@
>> #include "builtins.h"
>> #include "tm-constrs.h"
>> #include "rtl-iter.h"
>> +#include "gimple.h"
>>
>> /* This file should be included last. */
>> #include "target-def.h"
>> @@ -78,7 +79,7 @@ struct four_ints
>>
>> /* Forward function declarations. */
>> static bool arm_const_not_ok_for_debug_p (rtx);
>> -static bool arm_needs_doubleword_align (machine_mode, const_tree);
>> +static int arm_needs_doubleword_align (machine_mode, const_tree);
>> static int arm_compute_static_chain_stack_bytes (void);
>> static arm_stack_offsets *arm_get_frame_offsets (void);
>> static void arm_add_gc_roots (void);
>> @@ -6137,8 +6138,20 @@ aapcs_layout_arg (CUMULATIVE_ARGS *pcum, machine_mode mode,
>> /* C3 - For double-word aligned arguments, round the NCRN up to the
>> next even number. */
>> ncrn = pcum->aapcs_ncrn;
>> - if ((ncrn & 1) && arm_needs_doubleword_align (mode, type))
>> - ncrn++;
>> + if (ncrn & 1)
>> + {
>> + int res = arm_needs_doubleword_align (mode, type);
>> + /* Only warn during RTL expansion of call stmts, otherwise we would
>> + warn e.g. during gimplification even on functions that will be
>> + always inlined, and we'd warn multiple times. Don't warn when
>> + called in expand_function_start either, as we warn instead in
>> + arm_function_arg_boundary in that case. */
>> + if (res < 0 && warn_psabi && currently_expanding_gimple_stmt)
>> + inform (input_location, "parameter passing for argument of type "
>> + "%qT will change in GCC 7.1", type);
>> + if (res != 0)
>> + ncrn++;
>> + }
>>
>> nregs = ARM_NUM_REGS2(mode, type);
>>
>> @@ -6243,12 +6256,16 @@ arm_init_cumulative_args (CUMULATIVE_ARGS *pcum, tree fntype,
>> }
>> }
>>
>> -/* Return true if mode/type need doubleword alignment. */
>> -static bool
>> +/* Return 1 if double word alignment is required for argument passing.
>> + Return -1 if double word alignment used to be required for argument
>> + passing before PR77728 ABI fix, but is not required anymore.
>> + Return 0 if double word alignment is not required and wasn't requried
>> + before either. */
>> +static int
>> arm_needs_doubleword_align (machine_mode mode, const_tree type)
>> {
>> if (!type)
>> - return PARM_BOUNDARY < GET_MODE_ALIGNMENT (mode);
>> + return GET_MODE_ALIGNMENT (mode) > PARM_BOUNDARY;
>>
>> /* Scalar and vector types: Use natural alignment, i.e. of base type. */
>> if (!AGGREGATE_TYPE_P (type))
>> @@ -6258,12 +6275,21 @@ arm_needs_doubleword_align (machine_mode mode, const_tree type)
>> if (TREE_CODE (type) == ARRAY_TYPE)
>> return TYPE_ALIGN (TREE_TYPE (type)) > PARM_BOUNDARY;
>>
>> + int ret = 0;
>> /* Record/aggregate types: Use greatest member alignment of any member. */
>> for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
>> if (DECL_ALIGN (field) > PARM_BOUNDARY)
>> - return true;
>> + {
>> + if (TREE_CODE (field) == FIELD_DECL)
>> + return 1;
>> + else
>> + /* Before PR77728 fix, we were incorrectly considering also
>> + other aggregate fields, like VAR_DECLs, TYPE_DECLs etc.
>> + Make sure we can warn about that with -Wpsabi. */
>> + ret = -1;
>> + }
>>
>> - return false;
>> + return ret;
>> }
>>
>>
>> @@ -6320,10 +6346,15 @@ arm_function_arg (cumulative_args_t pcum_v, machine_mode mode,
>> }
>>
>> /* Put doubleword aligned quantities in even register pairs. */
>> - if (pcum->nregs & 1
>> - && ARM_DOUBLEWORD_ALIGN
>> - && arm_needs_doubleword_align (mode, type))
>> - pcum->nregs++;
>> + if ((pcum->nregs & 1) && ARM_DOUBLEWORD_ALIGN)
>> + {
>> + int res = arm_needs_doubleword_align (mode, type);
>> + if (res < 0 && warn_psabi)
>> + inform (input_location, "parameter passing for argument of type "
>> + "%qT will change in GCC 7.1", type);
>> + if (res != 0)
>> + pcum->nregs++;
>> + }
>>
>> /* Only allow splitting an arg between regs and memory if all preceding
>> args were allocated to regs. For args passed by reference we only count
>> @@ -6342,9 +6373,15 @@ arm_function_arg (cumulative_args_t pcum_v, machine_mode mode,
>> static unsigned int
>> arm_function_arg_boundary (machine_mode mode, const_tree type)
>> {
>> - return (ARM_DOUBLEWORD_ALIGN && arm_needs_doubleword_align (mode, type)
>> - ? DOUBLEWORD_ALIGNMENT
>> - : PARM_BOUNDARY);
>> + if (!ARM_DOUBLEWORD_ALIGN)
>> + return PARM_BOUNDARY;
>> +
>> + int res = arm_needs_doubleword_align (mode, type);
>> + if (res < 0 && warn_psabi)
>> + inform (input_location, "parameter passing for argument of type %qT "
>> + "will change in GCC 7.1", type);
>> +
>> + return res != 0 ? DOUBLEWORD_ALIGNMENT : PARM_BOUNDARY;
>> }
>>
>> static int
>> @@ -26402,8 +26439,15 @@ arm_setup_incoming_varargs (cumulative_args_t pcum_v,
>> if (pcum->pcs_variant <= ARM_PCS_AAPCS_LOCAL)
>> {
>> nregs = pcum->aapcs_ncrn;
>> - if ((nregs & 1) && arm_needs_doubleword_align (mode, type))
>> - nregs++;
>> + if (nregs & 1)
>> + {
>> + int res = arm_needs_doubleword_align (mode, type);
>> + if (res < 0 && warn_psabi)
>> + inform (input_location, "parameter passing for argument of "
>> + "type %qT will change in GCC 7.1", type);
>> + if (res != 0)
>> + nregs++;
>> + }
>> }
>> else
>> nregs = pcum->nregs;
>> diff --git gcc/testsuite/g++.dg/abi/pr77728-1.C gcc/testsuite/g++.dg/abi/pr77728-1.C
>> index e69de29..05f08c9 100644
>> --- gcc/testsuite/g++.dg/abi/pr77728-1.C
>> +++ gcc/testsuite/g++.dg/abi/pr77728-1.C
>> @@ -0,0 +1,171 @@
>> +// { dg-do compile { target arm_eabi } }
>> +// { dg-options "-Wpsabi" }
>> +
>> +#include <stdarg.h>
>> +
>> +template <int N>
>> +struct A { double p; };
>> +
>> +A<0> v;
>> +
>> +template <int N>
>> +struct B
>> +{
>> + typedef A<N> T;
>> + int i, j;
>> +};
>> +
>> +struct C : public B<0> {};
>> +struct D {};
>> +struct E : public D, C {};
>> +struct F : public B<1> {};
>> +struct G : public F { static double y; };
>> +struct H : public G {};
>> +struct I : public D { long long z; };
>> +struct J : public D { static double z; int i, j; };
>> +
>> +template <int N>
>> +struct K : public D { typedef A<N> T; int i, j; };
>> +
>> +struct L { static double h; int i, j; };
>> +
>> +int
>> +fn1 (int a, B<0> b) // { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" }
>> +{
>> + return a + b.i;
>> +}
>> +
>> +int
>> +fn2 (int a, B<1> b)
>> +{
>> + return a + b.i;
>> +}
>> +
>> +int
>> +fn3 (int a, L b) // { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" }
>> +{
>> + return a + b.i;
>> +}
>> +
>> +int
>> +fn4 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, B<0> n, ...)
>> +// { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" "" { target *-*-* } .-1 }
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn5 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, B<1> n, ...)
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn6 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, C n, ...)
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn7 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, E n, ...)
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn8 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, H n, ...)
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn9 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, I n, ...)
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn10 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, J n, ...)
>> +// { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" "" { target *-*-* } .-1 }
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn11 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, K<0> n, ...)
>> +// { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" "" { target *-*-* } .-1 }
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +int
>> +fn12 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k, int l, int m, K<2> n, ...)
>> +{
>> + va_list ap;
>> + va_start (ap, n);
>> + int x = va_arg (ap, int);
>> + va_end (ap);
>> + return x;
>> +}
>> +
>> +void
>> +test ()
>> +{
>> + static B<0> b0;
>> + static B<1> b1;
>> + static L l;
>> + static C c;
>> + static E e;
>> + static H h;
>> + static I i;
>> + static J j;
>> + static K<0> k0;
>> + static K<2> k2;
>> + fn1 (1, b0); // { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" }
>> + fn2 (1, b1);
>> + fn3 (1, l); // { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" }
>> + fn4 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, b0, 1, 2, 3, 4);
>> + // { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" "" { target *-*-* } .-1 }
>> + fn5 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, b1, 1, 2, 3, 4);
>> + fn6 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, c, 1, 2, 3, 4);
>> + fn7 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, e, 1, 2, 3, 4);
>> + fn8 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, h, 1, 2, 3, 4);
>> + fn9 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, i, 1, 2, 3, 4);
>> + fn10 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, j, 1, 2, 3, 4);
>> + // { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" "" { target *-*-* } .-1 }
>> + fn11 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, k0, 1, 2, 3, 4);
>> + // { dg-message "note: parameter passing for argument of type \[^\n\r]* will change in GCC 7\.1" "" { target *-*-* } .-1 }
>> + fn12 (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, k2, 1, 2, 3, 4);
>> +}
>>
>> Marek
>
> Marek
>