commit a13a5967a1f94744776d616ca84d5512b24bf546
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date:   Thu Oct 8 15:17:47 2015 +0100

    [AArch64] Add fmul+fcvt optimisation

diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h
index a8ac8d3..309dcfb 100644
--- a/gcc/config/aarch64/aarch64-protos.h
+++ b/gcc/config/aarch64/aarch64-protos.h
@@ -294,12 +294,14 @@ enum aarch64_symbol_type aarch64_classify_symbol (rtx, rtx);
 enum aarch64_symbol_type aarch64_classify_tls_symbol (rtx);
 enum reg_class aarch64_regno_regclass (unsigned);
 int aarch64_asm_preferred_eh_data_format (int, int);
+int aarch64_fpconst_pow_of_2 (rtx);
 machine_mode aarch64_hard_regno_caller_save_mode (unsigned, unsigned,
 						       machine_mode);
 int aarch64_hard_regno_mode_ok (unsigned, machine_mode);
 int aarch64_hard_regno_nregs (unsigned, machine_mode);
 int aarch64_simd_attr_length_move (rtx_insn *);
 int aarch64_uxt_size (int, HOST_WIDE_INT);
+int aarch64_vec_fpconst_pow_of_2 (rtx);
 rtx aarch64_final_eh_return_addr (void);
 rtx aarch64_legitimize_reload_address (rtx *, machine_mode, int, int, int);
 const char *aarch64_output_move_struct (rtx *operands);
diff --git a/gcc/config/aarch64/aarch64-simd.md b/gcc/config/aarch64/aarch64-simd.md
index 6a2ab61..3d2c496 100644
--- a/gcc/config/aarch64/aarch64-simd.md
+++ b/gcc/config/aarch64/aarch64-simd.md
@@ -1654,6 +1654,27 @@ (define_insn "l<fcvt_pattern><su_optab><VDQF:mode><fcvt_target>2"
   [(set_attr "type" "neon_fp_to_int_<Vetype><q>")]
 )
 
+(define_insn "*aarch64_fcvt<su_optab><VDQF:mode><fcvt_target>2_mult"
+  [(set (match_operand:<FCVT_TARGET> 0 "register_operand" "=w")
+	(FIXUORS:<FCVT_TARGET> (unspec:<FCVT_TARGET>
+			       [(mult:VDQF
+	 (match_operand:VDQF 1 "register_operand" "w")
+	 (match_operand:VDQF 2 "aarch64_fp_vec_pow2" ""))]
+			       UNSPEC_FRINTZ)))]
+  "TARGET_SIMD
+   && IN_RANGE (aarch64_vec_fpconst_pow_of_2 (operands[2]), 1,
+		GET_MODE_BITSIZE (GET_MODE_INNER (<VDQF:MODE>mode)))"
+  {
+    int fbits = aarch64_vec_fpconst_pow_of_2 (operands[2]);
+    char buf[64];
+    sprintf (buf, "fcvtz<su>\\t%%0.<Vtype>, %%1.<Vtype>, #%d", fbits);
+    output_asm_insn (buf, operands);
+    return "";
+  }
+  [(set_attr "type" "neon_fp_to_int_<Vetype><q>")]
+)
+
+
 (define_expand "<optab><VDQF:mode><fcvt_target>2"
   [(set (match_operand:<FCVT_TARGET> 0 "register_operand")
 	(FIXUORS:<FCVT_TARGET> (unspec:<FCVT_TARGET>
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 2ec76a5..9b76746 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -6808,6 +6808,19 @@ cost_plus:
 	  else
 	    *cost += extra_cost->fp[GET_MODE (x) == DFmode].toint;
 	}
+
+      /* We can combine fmul by a power of 2 followed by a fcvt into a single
+	 fixed-point fcvt.  */
+      if (GET_CODE (x) == MULT
+	  && ((VECTOR_MODE_P (mode)
+	       && aarch64_vec_fpconst_pow_of_2 (XEXP (x, 1)) > 0)
+	      || aarch64_fpconst_pow_of_2 (XEXP (x, 1)) > 0))
+	{
+	  *cost += rtx_cost (XEXP (x, 0), VOIDmode,
+			     (enum rtx_code) code, 0, speed);
+	  return true;
+	}
+
       *cost += rtx_cost (x, VOIDmode, (enum rtx_code) code, 0, speed);
       return true;
 
@@ -13386,6 +13399,54 @@ aarch64_reorg (void)
 #undef TARGET_MACHINE_DEPENDENT_REORG
 #define TARGET_MACHINE_DEPENDENT_REORG aarch64_reorg
 
+
+/* If X is a positive CONST_DOUBLE with a value that is a power of 2
+   return the log2 of that value.  Otherwise return -1.  */
+
+int
+aarch64_fpconst_pow_of_2 (rtx x)
+{
+  const REAL_VALUE_TYPE *r;
+
+  if (!CONST_DOUBLE_P (x))
+    return -1;
+
+  r = CONST_DOUBLE_REAL_VALUE (x);
+
+  if (REAL_VALUE_NEGATIVE (*r)
+      || REAL_VALUE_ISNAN (*r)
+      || REAL_VALUE_ISINF (*r)
+      || !real_isinteger (r, DFmode))
+    return -1;
+
+  return exact_log2 (real_to_integer (r));
+}
+
+/* If X is a vector of equal CONST_DOUBLE values and that value is
+   Y, return the aarch64_fpconst_pow_of_2 of Y.  Otherwise return -1.  */
+
+int
+aarch64_vec_fpconst_pow_of_2 (rtx x)
+{
+  if (GET_CODE (x) != CONST_VECTOR)
+    return -1;
+
+  if (GET_MODE_CLASS (GET_MODE (x)) != MODE_VECTOR_FLOAT)
+    return -1;
+
+  int firstval = aarch64_fpconst_pow_of_2 (CONST_VECTOR_ELT (x, 0));
+  if (firstval <= 0)
+    return -1;
+
+  int count = CONST_VECTOR_NUNITS (x);
+  int i;
+  for (i = 1; i < count; i++)
+    if (aarch64_fpconst_pow_of_2 (CONST_VECTOR_ELT (x, i)) != firstval)
+      return -1;
+
+  return firstval;
+}
+
 /* Implement TARGET_PROMOTED_TYPE to promote __fp16 to float.  */
 static tree
 aarch64_promoted_type (const_tree t)
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index bb821a3..6a9d52c 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -4287,6 +4287,25 @@ (define_insn "l<fcvt_pattern><su_optab><GPF:mode><GPI:mode>2"
   [(set_attr "type" "f_cvtf2i")]
 )
 
+(define_insn "*aarch64_fcvt<su_optab><GPF:mode><GPI:mode>2_mult"
+  [(set (match_operand:GPI 0 "register_operand" "=r")
+	(FIXUORS:GPI
+	  (mult:GPF
+	    (match_operand:GPF 1 "register_operand" "w")
+	    (match_operand:GPF 2 "aarch64_fp_pow2" "F"))))]
+  "TARGET_FLOAT
+   && IN_RANGE (aarch64_fpconst_pow_of_2 (operands[2]), 1,
+		GET_MODE_BITSIZE (<GPI:MODE>mode))"
+  {
+    int fbits = aarch64_fpconst_pow_of_2 (operands[2]);
+    char buf[64];
+    sprintf (buf, "fcvtz<su>\\t%%<GPI:w>0, %%<GPF:s>1, #%d", fbits);
+    output_asm_insn (buf, operands);
+    return "";
+  }
+  [(set_attr "type" "f_cvtf2i")]
+)
+
 ;; fma - no throw
 
 (define_insn "fma<mode>4"
diff --git a/gcc/config/aarch64/predicates.md b/gcc/config/aarch64/predicates.md
index 8af4b81..1bcbf62 100644
--- a/gcc/config/aarch64/predicates.md
+++ b/gcc/config/aarch64/predicates.md
@@ -87,6 +87,13 @@ (define_predicate "aarch64_fp_compare_operand"
        (and (match_code "const_double")
 	    (match_test "aarch64_float_const_zero_rtx_p (op)"))))
 
+(define_predicate "aarch64_fp_pow2"
+  (and (match_code "const_double")
+	(match_test "aarch64_fpconst_pow_of_2 (op) > 0")))
+
+(define_predicate "aarch64_fp_vec_pow2"
+  (match_test "aarch64_vec_fpconst_pow_of_2 (op) > 0"))
+
 (define_predicate "aarch64_plus_immediate"
   (and (match_code "const_int")
        (ior (match_test "aarch64_uimm12_shift (INTVAL (op))")
diff --git a/gcc/testsuite/gcc.target/aarch64/fmul_fcvt_1.c b/gcc/testsuite/gcc.target/aarch64/fmul_fcvt_1.c
new file mode 100644
index 0000000..5af8290
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/fmul_fcvt_1.c
@@ -0,0 +1,129 @@
+/* { dg-do run } */
+/* { dg-options "-save-temps -O2 -fno-inline" } */
+
+#define FUNC_DEFS(__a)	\
+int			\
+sffoo##__a (float x)	\
+{			\
+  return x * __a##.0f;	\
+}			\
+			\
+unsigned int		\
+usffoo##__a (float x)	\
+{			\
+  return x * __a##.0f;	\
+}			\
+			\
+long			\
+lsffoo##__a (float x)	\
+{			\
+  return x * __a##.0f;	\
+}			\
+			\
+unsigned long		\
+ulsffoo##__a (float x)	\
+{			\
+  return x * __a##.0f;	\
+}
+
+#define FUNC_DEFD(__a)	\
+long			\
+dffoo##__a (double x)	\
+{			\
+  return x * __a##.0;	\
+}			\
+			\
+unsigned long		\
+udffoo##__a (double x)	\
+{			\
+  return x * __a##.0;	\
+}			\
+int			\
+sdffoo##__a (double x)	\
+{			\
+  return x * __a##.0;	\
+}			\
+			\
+unsigned int		\
+usdffoo##__a (double x)	\
+{			\
+  return x * __a##.0;	\
+}
+
+FUNC_DEFS (4)
+FUNC_DEFD (4)
+/* { dg-final { scan-assembler "fcvtzs\tw\[0-9\], s\[0-9\]*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzs\tx\[0-9\], s\[0-9\]*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzs\tx\[0-9\], d\[0-9\]*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzs\tw\[0-9\], d\[0-9\]*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzu\tw\[0-9\], s\[0-9\]*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzu\tx\[0-9\], s\[0-9\]*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzu\tx\[0-9\], d\[0-9\]*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzu\tw\[0-9\], d\[0-9\]*.*#2" } } */
+
+FUNC_DEFS (8)
+FUNC_DEFD (8)
+/* { dg-final { scan-assembler "fcvtzs\tw\[0-9\], s\[0-9\]*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzs\tx\[0-9\], s\[0-9\]*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzs\tx\[0-9\], d\[0-9\]*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzs\tw\[0-9\], d\[0-9\]*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzu\tw\[0-9\], s\[0-9\]*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzu\tx\[0-9\], s\[0-9\]*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzu\tx\[0-9\], d\[0-9\]*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzu\tw\[0-9\], d\[0-9\]*.*#3" } } */
+
+FUNC_DEFS (16)
+FUNC_DEFD (16)
+/* { dg-final { scan-assembler "fcvtzs\tw\[0-9\], s\[0-9\]*.*#4" } } */
+/* { dg-final { scan-assembler "fcvtzs\tx\[0-9\], s\[0-9\]*.*#4" } } */
+/* { dg-final { scan-assembler "fcvtzs\tx\[0-9\], d\[0-9\]*.*#4" } } */
+/* { dg-final { scan-assembler "fcvtzs\tw\[0-9\], d\[0-9\]*.*#4" } } */
+/* { dg-final { scan-assembler "fcvtzu\tw\[0-9\], s\[0-9\]*.*#4" } } */
+/* { dg-final { scan-assembler "fcvtzu\tx\[0-9\], s\[0-9\]*.*#4" } } */
+/* { dg-final { scan-assembler "fcvtzu\tx\[0-9\], d\[0-9\]*.*#4" } } */
+/* { dg-final { scan-assembler "fcvtzu\tw\[0-9\], d\[0-9\]*.*#4" } } */
+
+
+#define FUNC_TESTS(__a, __b)					\
+do								\
+  {								\
+    if (sffoo##__a (__b) != (int)(__b * __a))			\
+      __builtin_abort ();					\
+    if (usffoo##__a (__b) != (unsigned int)(__b * __a))	\
+      __builtin_abort ();					\
+    if (lsffoo##__a (__b) != (long)(__b * __a))		\
+      __builtin_abort ();					\
+    if (ulsffoo##__a (__b) != (unsigned long)(__b * __a))	\
+      __builtin_abort ();					\
+  } while (0)
+
+#define FUNC_TESTD(__a, __b)					\
+do								\
+  {								\
+    if (dffoo##__a (__b) != (long)(__b * __a))			\
+      __builtin_abort ();					\
+    if (udffoo##__a (__b) != (unsigned long)(__b * __a))	\
+      __builtin_abort ();					\
+    if (sdffoo##__a (__b) != (int)(__b * __a))			\
+      __builtin_abort ();					\
+    if (usdffoo##__a (__b) != (unsigned int)(__b * __a))	\
+      __builtin_abort ();					\
+  } while (0)
+
+int
+main (void)
+{
+  float i;
+
+  for (i = -0.001; i < 32.0; i += 1.0f)
+    {
+      FUNC_TESTS (4, i);
+      FUNC_TESTS (8, i);
+      FUNC_TESTS (16, i);
+
+      FUNC_TESTD (4, i);
+      FUNC_TESTD (8, i);
+      FUNC_TESTD (16, i);
+    }
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/fmul_fcvt_2.c b/gcc/testsuite/gcc.target/aarch64/fmul_fcvt_2.c
new file mode 100644
index 0000000..39cf890
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/fmul_fcvt_2.c
@@ -0,0 +1,67 @@
+/* { dg-do run } */
+/* { dg-options "-save-temps -O2 -ftree-vectorize -fno-inline" } */
+
+#define N 1024
+
+#define FUNC_DEF(__a)		\
+void				\
+foo##__a (float *a, int *b)	\
+{				\
+  int i;			\
+  for (i = 0; i < N; i++)	\
+    b[i] = a[i] * __a##.0f;	\
+}
+
+FUNC_DEF (4)
+FUNC_DEF (8)
+FUNC_DEF (16)
+
+int ints[N];
+float floats[N];
+
+void
+reset_ints (int *arr)
+{
+  int i;
+
+  for (i = 0; i < N; i++)
+    arr[i] = 0;
+}
+
+void
+check_result (int *is, int n)
+{
+  int i;
+
+  for (i = 0; i < N; i++)
+    if (is[i] != i * n)
+      __builtin_abort ();
+}
+
+#define FUNC_CHECK(__a)		\
+do				\
+  {				\
+    reset_ints (ints);		\
+    foo##__a (floats, ints);	\
+    check_result (ints, __a);	\
+  } while (0)
+
+
+int
+main (void)
+{
+  int i;
+  for (i = 0; i < N; i++)
+    floats[i] = (float) i;
+
+  FUNC_CHECK (4);
+  FUNC_CHECK (8);
+  FUNC_CHECK (16);
+
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "fmul\tv\[0-9\]*.*" } } */
+/* { dg-final { scan-assembler "fcvtzs\tv\[0-9\].4s, v\[0-9\].4s*.*#2" } } */
+/* { dg-final { scan-assembler "fcvtzs\tv\[0-9\].4s, v\[0-9\].4s*.*#3" } } */
+/* { dg-final { scan-assembler "fcvtzs\tv\[0-9\].4s, v\[0-9\].4s*.*#4" } } */
