Transceiver52M: Add NEON complex-complex multiply

Complex-complex block multiples are used for phase rotation of
bursts. Optimization targeted from perf profiling.

Signed-off-by: Thomas Tsou <tom@tsou.cc>

1 files changed, 42 insertions, 0 deletions

diff --git a/Transceiver52M/arm/mult_neon.S b/Transceiver52M/arm/mult_neon.S
new file mode 100644
index 0000000..162846e
--- /dev/null
+++ b/Transceiver52M/arm/mult_neon.S
@@ -0,0 +1,42 @@
+/*
+ * NEON complex multiplication 
+ * Copyright (C) 2012,2013 Thomas Tsou <tom@tsou.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+	.syntax unified
+	.text
+	.align 2
+	.global neon_cmplx_mul_4n
+	.type neon_cmplx_mul_4n, %function
+neon_cmplx_mul_4n:
+	vpush       {q4-q7}
+.loop_mul:
+	vld2.32     {q0-q1}, [r1]!
+	vld2.32     {q2-q3}, [r2]!
+	vmul.f32         q4, q0, q2
+	vmul.f32         q5, q1, q3
+	vmul.f32         q6, q0, q3
+	vmul.f32         q7, q2, q1
+	vsub.f32         q8, q4, q5
+	vadd.f32         q9, q6, q7
+	vst2.32     {q8-q9}, [r0]!
+	subs             r3, #1
+	bne       .loop_mul
+	vpop       {q4-q7}
+	bx               lr
+	.size neon_cmplx_mul_4n, .-neon_cmplx_mul_4n
+	.section .note.GNU-stack,"",%progbits