This patch adds an rtl representation of a vector linear series
of the form:
a[I] = BASE + I * STEP
Like vec_duplicate;
- the new rtx can be used for both constant and non-constant vectors
- when used for constant vectors it is wrapped in a (const ...)
- the constant form is only used for variable-length vectors;
fixed-length vectors still use CONST_VECTOR
At the moment the code is restricted to integer elements, to avoid
concerns over floating-point rounding.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* doc/rtl.texi (vec_series): Document.
(const): Say that the operand can be a vec_series.
* rtl.def (VEC_SERIES): New rtx code.
* rtl.h (const_vec_series_p_1): Declare.
(const_vec_series_p): New function.
* emit-rtl.h (gen_const_vec_series): Declare.
(gen_vec_series): Likewise.
* emit-rtl.c (const_vec_series_p_1, gen_const_vec_series)
(gen_vec_series): Likewise.
* optabs.c (expand_mult_highpart): Use gen_const_vec_series.
* simplify-rtx.c (simplify_unary_operation): Handle negations
of vector series.
(simplify_binary_operation_series): New function.
(simplify_binary_operation_1): Use it. Handle VEC_SERIES.
(test_vector_ops_series): New function.
(test_vector_ops): Call it.
* config/powerpcspe/altivec.md (altivec_lvsl): Use
gen_const_vec_series.
(altivec_lvsr): Likewise.
* config/rs6000/altivec.md (altivec_lvsl, altivec_lvsr): Likewise.
Index: gcc/doc/rtl.texi
===================================================================
--- gcc/doc/rtl.texi 2017-10-23 11:41:39.185050437 +0100
+++ gcc/doc/rtl.texi 2017-10-23 11:41:41.547050496 +0100
@@ -1677,7 +1677,8 @@ are target-specific and typically repres
operator. @var{m} should be a valid address mode.
The second use of @code{const} is to wrap a vector operation.
-In this case @var{exp} must be a @code{vec_duplicate} expression.
+In this case @var{exp} must be a @code{vec_duplicate} or
+@code{vec_series} expression.
@findex high
@item (high:@var{m} @var{exp})
@@ -2722,6 +2723,10 @@ the same submodes as the input vector mo
number of output parts must be an integer multiple of the number of input
parts.
+@findex vec_series
+@item (vec_series:@var{m} @var{base} @var{step})
+This operation creates a vector in which element @var{i} is equal to
+@samp{@var{base} + @var{i}*@var{step}}. @var{m} must be a vector integer mode.
@end table
@node Conversions
Index: gcc/rtl.def
===================================================================
--- gcc/rtl.def 2017-10-23 11:40:11.378243915 +0100
+++ gcc/rtl.def 2017-10-23 11:41:41.549050496 +0100
@@ -710,6 +710,11 @@ DEF_RTL_EXPR(VEC_CONCAT, "vec_concat", "
an integer multiple of the number of input parts. */
DEF_RTL_EXPR(VEC_DUPLICATE, "vec_duplicate", "e", RTX_UNARY)
+/* Creation of a vector in which element I has the value BASE + I * STEP,
+ where BASE is the first operand and STEP is the second. The result
+ must have a vector integer mode. */
+DEF_RTL_EXPR(VEC_SERIES, "vec_series", "ee", RTX_BIN_ARITH)
+
/* Addition with signed saturation */
DEF_RTL_EXPR(SS_PLUS, "ss_plus", "ee", RTX_COMM_ARITH)
Index: gcc/rtl.h
===================================================================
--- gcc/rtl.h 2017-10-23 11:41:39.188050437 +0100
+++ gcc/rtl.h 2017-10-23 11:41:41.549050496 +0100
@@ -2816,6 +2816,51 @@ unwrap_const_vec_duplicate (T x)
return x;
}
+/* In emit-rtl.c. */
+extern bool const_vec_series_p_1 (const_rtx, rtx *, rtx *);
+
+/* Return true if X is a constant vector that contains a linear series
+ of the form:
+
+ { B, B + S, B + 2 * S, B + 3 * S, ... }
+
+ for a nonzero S. Store B and S in *BASE_OUT and *STEP_OUT on sucess. */
+
+inline bool
+const_vec_series_p (const_rtx x, rtx *base_out, rtx *step_out)
+{
+ if (GET_CODE (x) == CONST_VECTOR
+ && GET_MODE_CLASS (GET_MODE (x)) == MODE_VECTOR_INT)
+ return const_vec_series_p_1 (x, base_out, step_out);
+ if (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == VEC_SERIES)
+ {
+ *base_out = XEXP (XEXP (x, 0), 0);
+ *step_out = XEXP (XEXP (x, 0), 1);
+ return true;
+ }
+ return false;
+}
+
+/* Return true if X is a vector that contains a linear series of the
+ form:
+
+ { B, B + S, B + 2 * S, B + 3 * S, ... }
+
+ where B and S are constant or nonconstant. Store B and S in
+ *BASE_OUT and *STEP_OUT on sucess. */
+
+inline bool
+vec_series_p (const_rtx x, rtx *base_out, rtx *step_out)
+{
+ if (GET_CODE (x) == VEC_SERIES)
+ {
+ *base_out = XEXP (x, 0);
+ *step_out = XEXP (x, 1);
+ return true;
+ }
+ return const_vec_series_p (x, base_out, step_out);
+}
+
/* Return the unpromoted (outer) mode of SUBREG_PROMOTED_VAR_P subreg X. */
inline scalar_int_mode
Index: gcc/emit-rtl.h
===================================================================
--- gcc/emit-rtl.h 2017-10-23 11:41:32.369050264 +0100
+++ gcc/emit-rtl.h 2017-10-23 11:41:41.548050496 +0100
@@ -441,6 +441,9 @@ get_max_uid (void)
extern rtx gen_const_vec_duplicate (machine_mode, rtx);
extern rtx gen_vec_duplicate (machine_mode, rtx);
+extern rtx gen_const_vec_series (machine_mode, rtx, rtx);
+extern rtx gen_vec_series (machine_mode, rtx, rtx);
+
extern void set_decl_incoming_rtl (tree, rtx, bool);
/* Return a memory reference like MEMREF, but with its mode changed
Index: gcc/emit-rtl.c
===================================================================
--- gcc/emit-rtl.c 2017-10-23 11:41:39.186050437 +0100
+++ gcc/emit-rtl.c 2017-10-23 11:41:41.548050496 +0100
@@ -5796,6 +5796,69 @@ gen_vec_duplicate (machine_mode mode, rt
return gen_rtx_VEC_DUPLICATE (mode, x);
}
+/* A subroutine of const_vec_series_p that handles the case in which
+ X is known to be an integer CONST_VECTOR. */
+
+bool
+const_vec_series_p_1 (const_rtx x, rtx *base_out, rtx *step_out)
+{
+ unsigned int nelts = CONST_VECTOR_NUNITS (x);
+ if (nelts < 2)
+ return false;
+
+ scalar_mode inner = GET_MODE_INNER (GET_MODE (x));
+ rtx base = CONST_VECTOR_ELT (x, 0);
+ rtx step = simplify_binary_operation (MINUS, inner,
+ CONST_VECTOR_ELT (x, 1), base);
+ if (rtx_equal_p (step, CONST0_RTX (inner)))
+ return false;
+
+ for (unsigned int i = 2; i < nelts; ++i)
+ {
+ rtx diff = simplify_binary_operation (MINUS, inner,
+ CONST_VECTOR_ELT (x, i),
+ CONST_VECTOR_ELT (x, i - 1));
+ if (!rtx_equal_p (step, diff))
+ return false;
+ }
+
+ *base_out = base;
+ *step_out = step;
+ return true;
+}
+
+/* Generate a vector constant of mode MODE in which element I has
+ the value BASE + I * STEP. */
+
+rtx
+gen_const_vec_series (machine_mode mode, rtx base, rtx step)
+{
+ gcc_assert (CONSTANT_P (base) && CONSTANT_P (step));
+
+ int nunits = GET_MODE_NUNITS (mode);
+ rtvec v = rtvec_alloc (nunits);
+ scalar_mode inner_mode = GET_MODE_INNER (mode);
+ RTVEC_ELT (v, 0) = base;
+ for (int i = 1; i < nunits; ++i)
+ RTVEC_ELT (v, i) = simplify_gen_binary (PLUS, inner_mode,
+ RTVEC_ELT (v, i - 1), step);
+ return gen_rtx_raw_CONST_VECTOR (mode, v);
+}
+
+/* Generate a vector of mode MODE in which element I has the value
+ BASE + I * STEP. The result will be a constant if BASE and STEP
+ are both constants. */
+
+rtx
+gen_vec_series (machine_mode mode, rtx base, rtx step)
+{
+ if (step == const0_rtx)
+ return gen_vec_duplicate (mode, base);
+ if (CONSTANT_P (base) && CONSTANT_P (step))
+ return gen_const_vec_series (mode, base, step);
+ return gen_rtx_VEC_SERIES (mode, base, step);
+}
+
/* Generate a new vector constant for mode MODE and constant value
CONSTANT. */
Index: gcc/optabs.c
===================================================================
--- gcc/optabs.c 2017-10-23 11:41:32.369050264 +0100
+++ gcc/optabs.c 2017-10-23 11:41:41.549050496 +0100
@@ -5784,13 +5784,13 @@ expand_mult_highpart (machine_mode mode,
for (i = 0; i < nunits; ++i)
RTVEC_ELT (v, i) = GEN_INT (!BYTES_BIG_ENDIAN + (i & ~1)
+ ((i & 1) ? nunits : 0));
+ perm = gen_rtx_CONST_VECTOR (mode, v);
}
else
{
- for (i = 0; i < nunits; ++i)
- RTVEC_ELT (v, i) = GEN_INT (2 * i + (BYTES_BIG_ENDIAN ? 0 : 1));
+ int base = BYTES_BIG_ENDIAN ? 0 : 1;
+ perm = gen_const_vec_series (mode, GEN_INT (base), GEN_INT (2));
}
- perm = gen_rtx_CONST_VECTOR (mode, v);
return expand_vec_perm (mode, m1, m2, perm, target);
}
Index: gcc/simplify-rtx.c
===================================================================
--- gcc/simplify-rtx.c 2017-10-23 11:41:36.309050364 +0100
+++ gcc/simplify-rtx.c 2017-10-23 11:41:41.550050496 +0100
@@ -927,7 +927,7 @@ exact_int_to_float_conversion_p (const_r
simplify_unary_operation_1 (enum rtx_code code, machine_mode mode, rtx op)
{
enum rtx_code reversed;
- rtx temp, elt;
+ rtx temp, elt, base, step;
scalar_int_mode inner, int_mode, op_mode, op0_mode;
switch (code)
@@ -1185,6 +1185,22 @@ simplify_unary_operation_1 (enum rtx_cod
return simplify_gen_unary (TRUNCATE, int_mode, temp, inner);
}
}
+
+ if (vec_series_p (op, &base, &step))
+ {
+ /* Only create a new series if we can simplify both parts. In other
+ cases this isn't really a simplification, and it's not necessarily
+ a win to replace a vector operation with a scalar operation. */
+ scalar_mode inner_mode = GET_MODE_INNER (mode);
+ base = simplify_unary_operation (NEG, inner_mode, base, inner_mode);
+ if (base)
+ {
+ step = simplify_unary_operation (NEG, inner_mode,
+ step, inner_mode);
+ if (step)
+ return gen_vec_series (mode, base, step);
+ }
+ }
break;
case TRUNCATE:
@@ -2153,6 +2169,46 @@ simplify_binary_operation (enum rtx_code
return NULL_RTX;
}
+/* Subroutine of simplify_binary_operation_1 that looks for cases in
+ which OP0 and OP1 are both vector series or vector duplicates
+ (which are really just series with a step of 0). If so, try to
+ form a new series by applying CODE to the bases and to the steps.
+ Return null if no simplification is possible.
+
+ MODE is the mode of the operation and is known to be a vector
+ integer mode. */
+
+static rtx
+simplify_binary_operation_series (rtx_code code, machine_mode mode,
+ rtx op0, rtx op1)
+{
+ rtx base0, step0;
+ if (vec_duplicate_p (op0, &base0))
+ step0 = const0_rtx;
+ else if (!vec_series_p (op0, &base0, &step0))
+ return NULL_RTX;
+
+ rtx base1, step1;
+ if (vec_duplicate_p (op1, &base1))
+ step1 = const0_rtx;
+ else if (!vec_series_p (op1, &base1, &step1))
+ return NULL_RTX;
+
+ /* Only create a new series if we can simplify both parts. In other
+ cases this isn't really a simplification, and it's not necessarily
+ a win to replace a vector operation with a scalar operation. */
+ scalar_mode inner_mode = GET_MODE_INNER (mode);
+ rtx new_base = simplify_binary_operation (code, inner_mode, base0, base1);
+ if (!new_base)
+ return NULL_RTX;
+
+ rtx new_step = simplify_binary_operation (code, inner_mode, step0, step1);
+ if (!new_step)
+ return NULL_RTX;
+
+ return gen_vec_series (mode, new_base, new_step);
+}
+
/* Subroutine of simplify_binary_operation. Simplify a binary operation
CODE with result mode MODE, operating on OP0 and OP1. If OP0 and/or
OP1 are constant pool references, TRUEOP0 and TRUEOP1 represent the
@@ -2333,6 +2389,14 @@ simplify_binary_operation_1 (enum rtx_co
if (tem)
return tem;
}
+
+ /* Handle vector series. */
+ if (GET_MODE_CLASS (mode) == MODE_VECTOR_INT)
+ {
+ tem = simplify_binary_operation_series (code, mode, op0, op1);
+ if (tem)
+ return tem;
+ }
break;
case COMPARE:
@@ -2544,6 +2608,14 @@ simplify_binary_operation_1 (enum rtx_co
|| plus_minus_operand_p (op1))
&& (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
return tem;
+
+ /* Handle vector series. */
+ if (GET_MODE_CLASS (mode) == MODE_VECTOR_INT)
+ {
+ tem = simplify_binary_operation_series (code, mode, op0, op1);
+ if (tem)
+ return tem;
+ }
break;
case MULT:
@@ -3495,6 +3567,11 @@ simplify_binary_operation_1 (enum rtx_co
/* ??? There are simplifications that can be done. */
return 0;
+ case VEC_SERIES:
+ if (op1 == CONST0_RTX (GET_MODE_INNER (mode)))
+ return gen_vec_duplicate (mode, op0);
+ return 0;
+
case VEC_SELECT:
if (!VECTOR_MODE_P (mode))
{
@@ -6490,6 +6567,60 @@ test_vector_ops_duplicate (machine_mode
}
}
+/* Test vector simplifications involving VEC_SERIES in which the
+ operands and result have vector mode MODE. SCALAR_REG is a pseudo
+ register that holds one element of MODE. */
+
+static void
+test_vector_ops_series (machine_mode mode, rtx scalar_reg)
+{
+ /* Test unary cases with VEC_SERIES arguments. */
+ scalar_mode inner_mode = GET_MODE_INNER (mode);
+ rtx duplicate = gen_rtx_VEC_DUPLICATE (mode, scalar_reg);
+ rtx neg_scalar_reg = gen_rtx_NEG (inner_mode, scalar_reg);
+ rtx series_0_r = gen_rtx_VEC_SERIES (mode, const0_rtx, scalar_reg);
+ rtx series_0_nr = gen_rtx_VEC_SERIES (mode, const0_rtx, neg_scalar_reg);
+ rtx series_nr_1 = gen_rtx_VEC_SERIES (mode, neg_scalar_reg, const1_rtx);
+ rtx series_r_m1 = gen_rtx_VEC_SERIES (mode, scalar_reg, constm1_rtx);
+ rtx series_r_r = gen_rtx_VEC_SERIES (mode, scalar_reg, scalar_reg);
+ rtx series_nr_nr = gen_rtx_VEC_SERIES (mode, neg_scalar_reg,
+ neg_scalar_reg);
+ ASSERT_RTX_EQ (series_0_r,
+ simplify_unary_operation (NEG, mode, series_0_nr, mode));
+ ASSERT_RTX_EQ (series_r_m1,
+ simplify_unary_operation (NEG, mode, series_nr_1, mode));
+ ASSERT_RTX_EQ (series_r_r,
+ simplify_unary_operation (NEG, mode, series_nr_nr, mode));
+
+ /* Test that a VEC_SERIES with a zero step is simplified away. */
+ ASSERT_RTX_EQ (duplicate,
+ simplify_binary_operation (VEC_SERIES, mode,
+ scalar_reg, const0_rtx));
+
+ /* Test PLUS and MINUS with VEC_SERIES. */
+ rtx series_0_1 = gen_const_vec_series (mode, const0_rtx, const1_rtx);
+ rtx series_0_m1 = gen_const_vec_series (mode, const0_rtx, constm1_rtx);
+ rtx series_r_1 = gen_rtx_VEC_SERIES (mode, scalar_reg, const1_rtx);
+ ASSERT_RTX_EQ (series_r_r,
+ simplify_binary_operation (PLUS, mode, series_0_r,
+ duplicate));
+ ASSERT_RTX_EQ (series_r_1,
+ simplify_binary_operation (PLUS, mode, duplicate,
+ series_0_1));
+ ASSERT_RTX_EQ (series_r_m1,
+ simplify_binary_operation (PLUS, mode, duplicate,
+ series_0_m1));
+ ASSERT_RTX_EQ (series_0_r,
+ simplify_binary_operation (MINUS, mode, series_r_r,
+ duplicate));
+ ASSERT_RTX_EQ (series_r_m1,
+ simplify_binary_operation (MINUS, mode, duplicate,
+ series_0_1));
+ ASSERT_RTX_EQ (series_r_1,
+ simplify_binary_operation (MINUS, mode, duplicate,
+ series_0_m1));
+}
+
/* Verify some simplifications involving vectors. */
static void
@@ -6502,6 +6633,9 @@ test_vector_ops ()
{
rtx scalar_reg = make_test_reg (GET_MODE_INNER (mode));
test_vector_ops_duplicate (mode, scalar_reg);
+ if (GET_MODE_CLASS (mode) == MODE_VECTOR_INT
+ && GET_MODE_NUNITS (mode) > 2)
+ test_vector_ops_series (mode, scalar_reg);
}
}
}
Index: gcc/config/powerpcspe/altivec.md
===================================================================
--- gcc/config/powerpcspe/altivec.md 2017-10-23 11:41:32.366050264 +0100
+++ gcc/config/powerpcspe/altivec.md 2017-10-23 11:41:41.546050496 +0100
@@ -2456,13 +2456,10 @@ (define_expand "altivec_lvsl"
emit_insn (gen_altivec_lvsl_direct (operands[0], operands[1]));
else
{
- int i;
- rtx mask, perm[16], constv, vperm;
+ rtx mask, constv, vperm;
mask = gen_reg_rtx (V16QImode);
emit_insn (gen_altivec_lvsl_direct (mask, operands[1]));
- for (i = 0; i < 16; ++i)
- perm[i] = GEN_INT (i);
- constv = gen_rtx_CONST_VECTOR (V16QImode, gen_rtvec_v (16, perm));
+ constv = gen_const_vec_series (V16QImode, const0_rtx, const1_rtx);
constv = force_reg (V16QImode, constv);
vperm = gen_rtx_UNSPEC (V16QImode, gen_rtvec (3, mask, mask, constv),
UNSPEC_VPERM);
@@ -2488,13 +2485,10 @@ (define_expand "altivec_lvsr"
emit_insn (gen_altivec_lvsr_direct (operands[0], operands[1]));
else
{
- int i;
- rtx mask, perm[16], constv, vperm;
+ rtx mask, constv, vperm;
mask = gen_reg_rtx (V16QImode);
emit_insn (gen_altivec_lvsr_direct (mask, operands[1]));
- for (i = 0; i < 16; ++i)
- perm[i] = GEN_INT (i);
- constv = gen_rtx_CONST_VECTOR (V16QImode, gen_rtvec_v (16, perm));
+ constv = gen_const_vec_series (V16QImode, const0_rtx, const1_rtx);
constv = force_reg (V16QImode, constv);
vperm = gen_rtx_UNSPEC (V16QImode, gen_rtvec (3, mask, mask, constv),
UNSPEC_VPERM);
Index: gcc/config/rs6000/altivec.md
===================================================================
--- gcc/config/rs6000/altivec.md 2017-10-23 11:41:32.366050264 +0100
+++ gcc/config/rs6000/altivec.md 2017-10-23 11:41:41.547050496 +0100
@@ -2573,13 +2573,10 @@ (define_expand "altivec_lvsl"
emit_insn (gen_altivec_lvsl_direct (operands[0], operands[1]));
else
{
- int i;
- rtx mask, perm[16], constv, vperm;
+ rtx mask, constv, vperm;
mask = gen_reg_rtx (V16QImode);
emit_insn (gen_altivec_lvsl_direct (mask, operands[1]));
- for (i = 0; i < 16; ++i)
- perm[i] = GEN_INT (i);
- constv = gen_rtx_CONST_VECTOR (V16QImode, gen_rtvec_v (16, perm));
+ constv = gen_const_vec_series (V16QImode, const0_rtx, const1_rtx);
constv = force_reg (V16QImode, constv);
vperm = gen_rtx_UNSPEC (V16QImode, gen_rtvec (3, mask, mask, constv),
UNSPEC_VPERM);
@@ -2614,13 +2611,10 @@ (define_expand "altivec_lvsr"
emit_insn (gen_altivec_lvsr_direct (operands[0], operands[1]));
else
{
- int i;
- rtx mask, perm[16], constv, vperm;
+ rtx mask, constv, vperm;
mask = gen_reg_rtx (V16QImode);
emit_insn (gen_altivec_lvsr_direct (mask, operands[1]));
- for (i = 0; i < 16; ++i)
- perm[i] = GEN_INT (i);
- constv = gen_rtx_CONST_VECTOR (V16QImode, gen_rtvec_v (16, perm));
+ constv = gen_const_vec_series (V16QImode, const0_rtx, const1_rtx);
constv = force_reg (V16QImode, constv);
vperm = gen_rtx_UNSPEC (V16QImode, gen_rtvec (3, mask, mask, constv),
UNSPEC_VPERM);
