On Thu, Nov 21, 2013 at 8:26 AM, Wei Mi <w...@google.com> wrote:
> Hi,
>
> This patch works on the intrinsic calls handling issue in IVOPT mentioned
> here:
> http://gcc.gnu.org/ml/gcc-patches/2010-10/msg01295.html
>
> In find_interesting_uses_stmt, it changes
>
> arg = expr
> __builtin_xxx (arg)
>
> to
>
> arg = expr;
> tmp = addr_expr (mem_ref(arg));
> __builtin_xxx (tmp, ...)
>
> So mem_ref(arg) could be handled by find_interesting_uses_address, and
> an iv use of USE_ADDRESS type will be generated for expr, then a TMR
> will be generated for expr in rewrite_use_address. Expand pass is
> changed accordingly to keep the complex addressing mode not to be
> splitted for cse.
>
> With the patch we can handle the motivational case below.
>
> #include <x86intrin.h>
> extern __m128i arr[], d[];
> void test (void)
> {
> unsigned int b;
> for (b = 0; b < 1000; b += 2) {
> __m128i *p = (__m128i *)(&d[b]);
> __m128i a = _mm_load_si128(&arr[4*b+3]);
> __m128i v = _mm_loadu_si128(p);
> v = _mm_xor_si128(v, a);
> _mm_storeu_si128(p, v);
> }
> }
>
> gcc-r204792 Without the patch:
> .L2:
> movdqu (%rax), %xmm0
> subq $-128, %rdx
> addq $32, %rax
> pxor -128(%rdx), %xmm0
> movups %xmm0, -32(%rax)
> cmpq $arr+64048, %rdx
> jne .L2
>
> gcc-r204792 With the patch:
> .L2:
> movdqu d(%rax), %xmm0
> pxor arr+48(,%rax,4), %xmm0
> addq $32, %rax
> movups %xmm0, d-32(%rax)
> cmpq $16000, %rax
> jne .L2
>
> Following things to be addressed later:
> 1. TER needs to be extended to handle the case when TMR is csed.
>
> 2. For more complex cases to work, besides this patch, we also need to
> tune the AVG_LOOP_NITER, which is now set to 5, and it limits
> induction variables merging a lot. Increasing the parameter to a
> larger one could remove some induction variable in critical loop in
> some our benchmarks. reg pressure estimation may also need to be
> tuned. I will address it in a separate patch.
>
> 3. Now the information about which param of a builtin is of memory
> reference type is simply listed as a switch-case in
> builtin_has_mem_ref_p and ix86_builtin_has_mem_ref_p. This is not
> ideal but there is no infrastructure to describe it in existing
> implementation. More detailed information such as parameter and call
> side-effect will be important for more precise alias and may worth
> some work. Maybe the refinement about this patch could be done after
> that.
>
> regression and bootstrap pass on x86_64-linux-gnu. ok for trunk?
So what you are doing is basically not only rewriting memory references
to possibly use TARGET_MEM_REF but also address uses to use
&TARGET_MEM_REF. I think this is a good thing in general
(given instructions like x86 lea) and I would not bother distinguishing
the different kind of uses.
Richard.
> Thanks,
> Wei.
>
> 2013-11-20 Wei Mi <w...@google.com>
>
> * expr.c (expand_expr_addr_expr_1): Not to split TMR.
> (expand_expr_real_1): Ditto.
> * targhooks.c (default_builtin_has_mem_ref_p): Default
> builtin.
> * tree-ssa-loop-ivopts.c (struct iv): Add field builtin_mem_param.
> (alloc_iv): Ditto.
> (remove_unused_ivs): Ditto.
> (builtin_has_mem_ref_p): New function.
> (find_interesting_uses_stmt): Special handling of builtins.
> * gimple-expr.c (is_gimple_address): Add handling of TMR.
> * gimple-expr.h (is_gimple_addressable): Ditto.
> * config/i386/i386.c (ix86_builtin_has_mem_ref_p): New target hook.
> (ix86_atomic_assign_expand_fenv): Ditto.
> (ix86_expand_special_args_builtin): Special handling of TMR for
> builtin.
> * target.def (builtin_has_mem_ref_p): New hook.
> * doc/tm.texi.in: Ditto.
> * doc/tm.texi: Generated.
>
> 2013-11-20 Wei Mi <w...@google.com>
>
> * gcc.dg/tree-ssa/ivopt_5.c: New test.
>
> Index: expr.c
> ===================================================================
> --- expr.c (revision 204792)
> +++ expr.c (working copy)
> @@ -7467,7 +7467,19 @@ expand_expr_addr_expr_1 (tree exp, rtx t
> tem = fold_build_pointer_plus (tem, TREE_OPERAND (exp, 1));
> return expand_expr (tem, target, tmode, modifier);
> }
> + case TARGET_MEM_REF:
> + {
> + int old_cse_not_expected;
> + addr_space_t as
> + = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))));
>
> + result = addr_for_mem_ref (exp, as, true);
> + old_cse_not_expected = cse_not_expected;
> + cse_not_expected = true;
> + result = memory_address_addr_space (tmode, result, as);
> + cse_not_expected = old_cse_not_expected;
> + return result;
> + }
> case CONST_DECL:
> /* Expand the initializer like constants above. */
> result = XEXP (expand_expr_constant (DECL_INITIAL (exp),
> @@ -9526,9 +9538,13 @@ expand_expr_real_1 (tree exp, rtx target
> = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))));
> enum insn_code icode;
> unsigned int align;
> + int old_cse_not_expected;
>
> op0 = addr_for_mem_ref (exp, as, true);
> + old_cse_not_expected = cse_not_expected;
> + cse_not_expected = true;
> op0 = memory_address_addr_space (mode, op0, as);
> + cse_not_expected = old_cse_not_expected;
> temp = gen_rtx_MEM (mode, op0);
> set_mem_attributes (temp, exp, 0);
> set_mem_addr_space (temp, as);
> Index: targhooks.c
> ===================================================================
> --- targhooks.c (revision 204792)
> +++ targhooks.c (working copy)
> @@ -566,6 +566,13 @@ default_builtin_reciprocal (unsigned int
> }
>
> bool
> +default_builtin_has_mem_ref_p (int built_in_function ATTRIBUTE_UNUSED,
> + int i ATTRIBUTE_UNUSED)
> +{
> + return false;
> +}
> +
> +bool
> hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
> cumulative_args_t ca ATTRIBUTE_UNUSED,
> enum machine_mode mode ATTRIBUTE_UNUSED,
> Index: tree-ssa-loop-ivopts.c
> ===================================================================
> --- tree-ssa-loop-ivopts.c (revision 204792)
> +++ tree-ssa-loop-ivopts.c (working copy)
> @@ -135,6 +135,8 @@ struct iv
> tree ssa_name; /* The ssa name with the value. */
> bool biv_p; /* Is it a biv? */
> bool have_use_for; /* Do we already have a use for it? */
> + bool builtin_mem_param; /* Used as param of a builtin, so it could not be
> + removed by remove_unused_ivs. */
> unsigned use_id; /* The identifier in the use if it is the case. */
> };
>
> @@ -952,6 +954,7 @@ alloc_iv (tree base, tree step)
> iv->step = step;
> iv->biv_p = false;
> iv->have_use_for = false;
> + iv->builtin_mem_param = false;
> iv->use_id = 0;
> iv->ssa_name = NULL_TREE;
>
> @@ -1874,13 +1877,36 @@ find_invariants_stmt (struct ivopts_data
> }
> }
>
> +/* Find whether the Ith param of the BUILTIN is a mem
> + reference. If I is -1, it returns whether the BUILTIN
> + contains any mem reference type param. */
> +
> +static bool
> +builtin_has_mem_ref_p (gimple builtin, int i)
> +{
> + tree fndecl = gimple_call_fndecl (builtin);
> + if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
> + {
> + switch (DECL_FUNCTION_CODE (fndecl))
> + {
> + case BUILT_IN_PREFETCH:
> + if (i == -1 || i == 0)
> + return true;
> + }
> + }
> + else if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD)
> + return targetm.builtin_has_mem_ref_p ((int) DECL_FUNCTION_CODE
> (fndecl), i);
> +
> + return false;
> +}
> +
> /* Finds interesting uses of induction variables in the statement STMT. */
>
> static void
> find_interesting_uses_stmt (struct ivopts_data *data, gimple stmt)
> {
> struct iv *iv;
> - tree op, *lhs, *rhs;
> + tree op, *lhs, *rhs, callee;
> ssa_op_iter iter;
> use_operand_p use_p;
> enum tree_code code;
> @@ -1937,6 +1963,74 @@ find_interesting_uses_stmt (struct ivopt
>
> call (memory). */
> }
> + else if (is_gimple_call (stmt)
> + && (callee = gimple_call_fndecl (stmt))
> + && is_builtin_fn (callee)
> + && builtin_has_mem_ref_p (stmt, -1))
> + {
> + size_t i;
> + for (i = 0; i < gimple_call_num_args (stmt); i++)
> + {
> + if (builtin_has_mem_ref_p (stmt, i))
> + {
> + gimple def, g;
> + gimple_seq seq = NULL;
> + tree type, mem, addr, rhs;
> + tree *arg = gimple_call_arg_ptr (stmt, i);
> + location_t loc = gimple_location (stmt);
> + gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
> +
> + if (TREE_CODE (*arg) != SSA_NAME)
> + continue;
> +
> + def = SSA_NAME_DEF_STMT (*arg);
> + gcc_assert (gimple_code (def) == GIMPLE_PHI
> + || is_gimple_assign (def));
> + /* Suppose we have the case:
> + arg = expr;
> + call (arg)
> + If the expr is not like the form: &MEM(...), change it to:
> + arg = expr;
> + tmp = &MEM(arg);
> + call(tmp);
> + then try to find interesting uses address in MEM(arg). */
> + if (is_gimple_assign (def)
> + && (rhs = gimple_assign_rhs1(def))
> + && TREE_CODE (rhs) == ADDR_EXPR
> + && REFERENCE_CLASS_P (TREE_OPERAND (rhs, 0)))
> + {
> + iv = get_iv (data, *arg);
> + if (iv && !iv->builtin_mem_param)
> + iv->builtin_mem_param = true;
> +
> + find_interesting_uses_address (data, def,
> + &TREE_OPERAND (rhs, 0));
> + }
> + else
> + {
> + mem = build2 (MEM_REF, TREE_TYPE (*arg), *arg,
> + build_int_cst (TREE_TYPE (*arg), 0));
> + type = build_pointer_type (TREE_TYPE (*arg));
> + addr = build1 (ADDR_EXPR, type, mem);
> + g = gimple_build_assign_with_ops (ADDR_EXPR,
> + make_ssa_name (type,
> NULL),
> + addr, NULL);
> + gimple_call_set_arg (stmt, i, gimple_assign_lhs (g));
> + update_stmt (stmt);
> + gimple_set_location (g, loc);
> + gimple_seq_add_stmt_without_update (&seq, g);
> + gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
> + find_interesting_uses_address (data, g,
> &TREE_OPERAND (addr, 0));
> + }
> + }
> + else
> + {
> + tree arg = gimple_call_arg (stmt, i);
> + find_interesting_uses_op (data, arg);
> + }
> + }
> + return;
> + }
>
> if (gimple_code (stmt) == GIMPLE_PHI
> && gimple_bb (stmt) == data->current_loop->header)
> @@ -6507,10 +6601,10 @@ remove_unused_ivs (struct ivopts_data *d
> && !integer_zerop (info->iv->step)
> && !info->inv_id
> && !info->iv->have_use_for
> + && !info->iv->builtin_mem_param
> && !info->preserve_biv)
> {
> bitmap_set_bit (toremove, SSA_NAME_VERSION (info->iv->ssa_name));
> -
> tree def = info->iv->ssa_name;
>
> if (MAY_HAVE_DEBUG_STMTS && SSA_NAME_DEF_STMT (def))
> Index: gimple-expr.c
> ===================================================================
> --- gimple-expr.c (revision 204792)
> +++ gimple-expr.c (working copy)
> @@ -633,7 +633,8 @@ is_gimple_address (const_tree t)
> op = TREE_OPERAND (op, 0);
> }
>
> - if (CONSTANT_CLASS_P (op) || TREE_CODE (op) == MEM_REF)
> + if (CONSTANT_CLASS_P (op) || TREE_CODE (op) == MEM_REF
> + || TREE_CODE (op) == TARGET_MEM_REF)
> return true;
>
> switch (TREE_CODE (op))
> Index: gimple-expr.h
> ===================================================================
> --- gimple-expr.h (revision 204792)
> +++ gimple-expr.h (working copy)
> @@ -122,7 +122,8 @@ static inline bool
> is_gimple_addressable (tree t)
> {
> return (is_gimple_id (t) || handled_component_p (t)
> - || TREE_CODE (t) == MEM_REF);
> + || TREE_CODE (t) == MEM_REF
> + || TREE_CODE (t) == TARGET_MEM_REF);
> }
>
> /* Return true if T is a valid gimple constant. */
> Index: config/i386/i386.c
> ===================================================================
> --- config/i386/i386.c (revision 204792)
> +++ config/i386/i386.c (working copy)
> @@ -29639,6 +29639,50 @@ ix86_init_mmx_sse_builtins (void)
> }
> }
>
> +/* Return whether the Ith param of the BUILTIN_FUNCTION
> + is a memory reference. If I == -1, return whether the
> + BUILTIN_FUNCTION contains any memory reference param. */
> +
> +static bool
> +ix86_builtin_has_mem_ref_p (int builtin_function, int i)
> +{
> + switch ((enum ix86_builtins) builtin_function)
> + {
> + /* LOAD. */
> + case IX86_BUILTIN_LOADHPS:
> + case IX86_BUILTIN_LOADLPS:
> + case IX86_BUILTIN_LOADHPD:
> + case IX86_BUILTIN_LOADLPD:
> + if (i == -1 || i == 1)
> + return true;
> + break;
> + case IX86_BUILTIN_LOADUPS:
> + case IX86_BUILTIN_LOADUPD:
> + case IX86_BUILTIN_LOADDQU:
> + case IX86_BUILTIN_LOADUPD256:
> + case IX86_BUILTIN_LOADUPS256:
> + case IX86_BUILTIN_LOADDQU256:
> + case IX86_BUILTIN_LDDQU256:
> + if (i == -1 || i == 0)
> + return true;
> + break;
> + /* STORE. */
> + case IX86_BUILTIN_STOREHPS:
> + case IX86_BUILTIN_STORELPS:
> + case IX86_BUILTIN_STOREUPS:
> + case IX86_BUILTIN_STOREUPD:
> + case IX86_BUILTIN_STOREDQU:
> + case IX86_BUILTIN_STOREUPD256:
> + case IX86_BUILTIN_STOREUPS256:
> + case IX86_BUILTIN_STOREDQU256:
> + if (i == -1 || i == 0)
> + return true;
> + default:
> + break;
> + }
> + return false;
> +}
> +
> /* This adds a condition to the basic_block NEW_BB in function FUNCTION_DECL
> to return a pointer to VERSION_DECL if the outcome of the expression
> formed by PREDICATE_CHAIN is true. This function will be called during
> @@ -32525,7 +32569,13 @@ ix86_expand_special_args_builtin (const
> if (i == memory)
> {
> /* This must be the memory operand. */
> - op = force_reg (Pmode, convert_to_mode (Pmode, op, 1));
> +
> + /* We expect the builtin could be expanded to rtl with memory
> + operand and proper addressing mode will be kept as specified
> + in TARGET_MEM_REF. */
> + if (!(TREE_CODE (arg) == ADDR_EXPR
> + && TREE_CODE (TREE_OPERAND (arg, 0)) == TARGET_MEM_REF))
> + op = force_reg (Pmode, convert_to_mode (Pmode, op, 1));
> op = gen_rtx_MEM (mode, op);
> gcc_assert (GET_MODE (op) == mode
> || GET_MODE (op) == VOIDmode);
> @@ -43737,6 +43787,9 @@ ix86_atomic_assign_expand_fenv (tree *ho
> #undef TARGET_BUILTIN_RECIPROCAL
> #define TARGET_BUILTIN_RECIPROCAL ix86_builtin_reciprocal
>
> +#undef TARGET_BUILTIN_HAS_MEM_REF_P
> +#define TARGET_BUILTIN_HAS_MEM_REF_P ix86_builtin_has_mem_ref_p
> +
> #undef TARGET_ASM_FUNCTION_EPILOGUE
> #define TARGET_ASM_FUNCTION_EPILOGUE ix86_output_function_epilogue
>
> Index: doc/tm.texi
> ===================================================================
> --- doc/tm.texi (revision 204792)
> +++ doc/tm.texi (working copy)
> @@ -709,6 +709,12 @@ If a target implements string objects th
> If a target implements string objects then this hook should should
> provide a facility to check the function arguments in @var{args_list}
> against the format specifiers in @var{format_arg} where the type of
> @var{format_arg} is one recognized as a valid string reference type.
> @end deftypefn
>
> +@deftypefn {Target Hook} bool TARGET_BUILTIN_HAS_MEM_REF_P (int
> @var{builtin_function}, int @var{i})
> +This hook return whether the @var{i}th param of the @var{builtin_function}
> +is a memory reference. If @var{i} is -1, return whether the
> @var{builtin_function}
> +contains any memory reference type param.
> +@end deftypefn
> +
> @deftypefn {Target Hook} void TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE (void)
> This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}
> but is called when the optimize level is changed via an attribute or
> Index: doc/tm.texi.in
> ===================================================================
> --- doc/tm.texi.in (revision 204792)
> +++ doc/tm.texi.in (working copy)
> @@ -697,6 +697,8 @@ should use @code{TARGET_HANDLE_C_OPTION}
>
> @hook TARGET_CHECK_STRING_OBJECT_FORMAT_ARG
>
> +@hook TARGET_BUILTIN_HAS_MEM_REF_P
> +
> @hook TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE
>
> @defmac C_COMMON_OVERRIDE_OPTIONS
> Index: target.def
> ===================================================================
> --- target.def (revision 204792)
> +++ target.def (working copy)
> @@ -1742,6 +1742,14 @@ HOOK_VECTOR_END (vectorize)
> #undef HOOK_PREFIX
> #define HOOK_PREFIX "TARGET_"
>
> +DEFHOOK
> +(builtin_has_mem_ref_p,
> + "This hook return whether the @var{i}th param of the
> @var{builtin_function}\n\
> +is a memory reference. If @var{i} is -1, return whether the
> @var{builtin_function}\n\
> +contains any memory reference type param.",
> + bool, (int builtin_function, int i),
> + default_builtin_has_mem_ref_p)
> +
> /* Allow target specific overriding of option settings after options have
> been changed by an attribute or pragma or when it is reset at the
> end of the code affected by an attribute or pragma. */
> Index: testsuite/gcc.dg/tree-ssa/ivopt_5.c
> ===================================================================
> --- testsuite/gcc.dg/tree-ssa/ivopt_5.c (revision 0)
> +++ testsuite/gcc.dg/tree-ssa/ivopt_5.c (revision 0)
> @@ -0,0 +1,21 @@
> +/* { dg-do compile { target {{ i?86-*-* x86_64-*-* } && lp64 } } } */
> +/* { dg-options "-O2 -m64 -fdump-tree-ivopts-details" } */
> +
> +/* Make sure only one iv is selected after IVOPT. */
> +
> +#include <x86intrin.h>
> +extern __m128i arr[], d[];
> +void test (void)
> +{
> + unsigned int b;
> + for (b = 0; b < 1000; b += 2) {
> + __m128i *p = (__m128i *)(&d[b]);
> + __m128i a = _mm_load_si128(&arr[4*b+3]);
> + __m128i v = _mm_loadu_si128(p);
> + v = _mm_xor_si128(v, a);
> + _mm_storeu_si128(p, v);
> + }
> +}
> +
> +/* { dg-final { scan-tree-dump-times "PHI <ivtmp" 1 "ivopts"} } */
> +/* { dg-final { cleanup-tree-dump "ivopts" } } */
