ARM: SIMD optimizations moved to a separate .S file

This should be the last step in providing full armv4t compatibility
with CPU features runtime autodetection in pixman.

4 files changed, 359 insertions, 32 deletions

diff --git a/configure.ac b/configure.ac
index 4668715..ed7d16a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -361,30 +361,24 @@ AC_SUBST(VMX_CFLAGS)
 
 AM_CONDITIONAL(USE_VMX, test $have_vmx_intrinsics = yes)
 
-dnl ===========================================================================
-dnl Check for ARM SIMD instructions
-ARM_SIMD_CFLAGS=""
-
+dnl ==========================================================================
+dnl Check if assembler is gas compatible and supports ARM SIMD instructions
 have_arm_simd=no
 AC_MSG_CHECKING(whether to use ARM SIMD assembler)
-# check with default CFLAGS in case the toolchain turns on a sufficiently recent -mcpu=
-AC_COMPILE_IFELSE([
-int main () {
-    asm("uqadd8 r1, r1, r2");
-    return 0;
-}], have_arm_simd=yes,
-    # check again with an explicit -mcpu= in case the toolchain defaults to an
-    # older one; note that uqadd8 isn't available in Thumb mode on arm1136j-s
-    # so we force ARM mode
-    ARM_SIMD_CFLAGS="-mcpu=arm1136j-s -marm"
-    xserver_save_CFLAGS=$CFLAGS
-    CFLAGS="$ARM_SIMD_CFLAGS $CFLAGS"
-    AC_COMPILE_IFELSE([
-    int main () {
-        asm("uqadd8 r1, r1, r2");
-        return 0;
-    }], have_arm_simd=yes)
-    CFLAGS=$xserver_save_CFLAGS)
+xserver_save_CFLAGS=$CFLAGS
+CFLAGS="-x assembler-with-cpp $CFLAGS"
+AC_COMPILE_IFELSE([[
+.text
+.arch armv6
+.object_arch armv4
+.arm
+.altmacro
+#ifndef __ARM_EABI__
+#error EABI is required (to be sure that calling conventions are compatible)
+#endif
+pld [r0]
+uqadd8 r0, r0, r0]], have_arm_simd=yes)
+CFLAGS=$xserver_save_CFLAGS
 
 AC_ARG_ENABLE(arm-simd,
    [AC_HELP_STRING([--disable-arm-simd],
@@ -396,20 +390,16 @@ if test $enable_arm_simd = no ; then
 fi
 
 if test $have_arm_simd = yes ; then
-   AC_DEFINE(USE_ARM_SIMD, 1, [use ARM SIMD compiler intrinsics])
-else
-   ARM_SIMD_CFLAGS=
+   AC_DEFINE(USE_ARM_SIMD, 1, [use ARM SIMD assembly optimizations])
 fi
 
+AM_CONDITIONAL(USE_ARM_SIMD, test $have_arm_simd = yes)
+
 AC_MSG_RESULT($have_arm_simd)
 if test $enable_arm_simd = yes && test $have_arm_simd = no ; then
    AC_MSG_ERROR([ARM SIMD intrinsics not detected])
 fi
 
-AC_SUBST(ARM_SIMD_CFLAGS)
-
-AM_CONDITIONAL(USE_ARM_SIMD, test $have_arm_simd = yes)
-
 dnl ==========================================================================
 dnl Check if assembler is gas compatible and supports NEON instructions
 have_arm_neon=no
diff --git a/pixman/Makefile.am b/pixman/Makefile.am
index 5a0e7a9..66ad7f0 100644
--- a/pixman/Makefile.am
+++ b/pixman/Makefile.am
@@ -97,12 +97,14 @@ endif
 if USE_ARM_SIMD
 noinst_LTLIBRARIES += libpixman-arm-simd.la
 libpixman_arm_simd_la_SOURCES = \
-	pixman-arm-simd.c
-libpixman_arm_simd_la_CFLAGS = $(DEP_CFLAGS) $(ARM_SIMD_CFLAGS)
+	pixman-arm-simd.c	\
+	pixman-arm-common.h	\
+	pixman-arm-simd-asm.S
+libpixman_arm_simd_la_CFLAGS = $(DEP_CFLAGS)
 libpixman_arm_simd_la_LIBADD = $(DEP_LIBS)
 libpixman_1_la_LIBADD += libpixman-arm-simd.la
 
-ASM_CFLAGS_arm_simd=$(ARM_SIMD_CFLAGS)
+ASM_CFLAGS_arm_simd=
 endif
 
 # arm neon code
@@ -110,6 +112,7 @@ if USE_ARM_NEON
 noinst_LTLIBRARIES += libpixman-arm-neon.la
 libpixman_arm_neon_la_SOURCES = \
         pixman-arm-neon.c	\
+        pixman-arm-common.h	\
         pixman-arm-neon-asm.S	\
         pixman-arm-neon-asm.h
 libpixman_arm_neon_la_CFLAGS = $(DEP_CFLAGS)
diff --git a/pixman/pixman-arm-simd-asm.S b/pixman/pixman-arm-simd-asm.S
new file mode 100644
index 0000000..1a1a0d6
--- /dev/null
+++ b/pixman/pixman-arm-simd-asm.S
@@ -0,0 +1,330 @@
+/*
+ * Copyright © 2008 Mozilla Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of Mozilla Corporation not be used in
+ * advertising or publicity pertaining to distribution of the software without
+ * specific, written prior permission.  Mozilla Corporation makes no
+ * representations about the suitability of this software for any purpose.  It
+ * is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ *
+ * Author:  Jeff Muizelaar (jeff@infidigm.net)
+ *
+ */
+
+/* Prevent the stack from becoming executable */
+#if defined(__linux__) && defined(__ELF__)
+.section .note.GNU-stack,"",%progbits
+#endif
+
+	.text
+	.arch armv6
+	.object_arch armv4
+	.arm
+	.altmacro
+
+/* Supplementary macro for setting function attributes */
+.macro pixman_asm_function fname
+	.func fname
+	.global fname
+#ifdef __ELF__
+	.hidden fname
+	.type fname, %function
+#endif
+fname:
+.endm
+
+/*
+ * The code below was generated by gcc 4.3.4 from the commented out
+ * functions in 'pixman-arm-simd.c' file with the following optimization
+ * options: "-O3 -mcpu=arm1136jf-s -fomit-frame-pointer"
+ *
+ * TODO: replace gcc generated code with hand tuned versions because
+ * the code quality is not very good, introduce symbolic register
+ * aliases for better readability and maintainability.
+ */
+
+pixman_asm_function pixman_composite_add_8000_8000_asm_armv6
+	push	{r4, r5, r6, r7, r8, r9, r10, r11}
+	mov	r10, r1
+	sub	sp, sp, #4
+	subs	r10, r10, #1
+	mov	r11, r0
+	mov	r8, r2
+	str	r3, [sp]
+	ldr	r7, [sp, #36]
+	bcc	0f
+6:	cmp	r11, #0
+	beq	1f
+	orr	r3, r8, r7
+	tst	r3, #3
+	beq	2f
+	mov	r1, r8
+	mov	r0, r7
+	mov	r12, r11
+	b	3f
+5:	tst	r3, #3
+	beq	4f
+3:	ldrb	r2, [r0], #1
+	subs	r12, r12, #1
+	ldrb	r3, [r1]
+	uqadd8	r3, r2, r3
+	strb	r3, [r1], #1
+	orr	r3, r1, r0
+	bne	5b
+1:	ldr	r3, [sp]
+	add	r8, r8, r3
+	ldr	r3, [sp, #40]
+	add	r7, r7, r3
+10:	subs	r10, r10, #1
+	bcs	6b
+0:	add	sp, sp, #4
+	pop	{r4, r5, r6, r7, r8, r9, r10, r11}
+	bx	lr
+2:	mov	r12, r11
+	mov	r1, r8
+	mov	r0, r7
+4:	cmp	r12, #3
+	subgt	r6, r12, #4
+	movgt	r9, r12
+	lsrgt	r5, r6, #2
+	addgt	r3, r5, #1
+	movgt	r12, #0
+	lslgt	r4, r3, #2
+	ble	7f
+8:	ldr	r3, [r0, r12]
+	ldr	r2, [r1, r12]
+	uqadd8	r3, r3, r2
+	str	r3, [r1, r12]
+	add	r12, r12, #4
+	cmp	r12, r4
+	bne	8b
+	sub	r3, r9, #4
+	bic	r3, r3, #3
+	add	r3, r3, #4
+	subs	r12, r6, r5, lsl #2
+	add	r1, r1, r3
+	add	r0, r0, r3
+	beq	1b
+7:	mov	r4, #0
+9:	ldrb	r3, [r1, r4]
+	ldrb	r2, [r0, r4]
+	uqadd8	r3, r2, r3
+	strb	r3, [r1, r4]
+	add	r4, r4, #1
+	cmp	r4, r12
+	bne	9b
+	ldr	r3, [sp]
+	add	r8, r8, r3
+	ldr	r3, [sp, #40]
+	add	r7, r7, r3
+	b	10b
+.endfunc
+
+pixman_asm_function pixman_composite_over_8888_8888_asm_armv6
+	push	{r4, r5, r6, r7, r8, r9, r10, r11}
+	sub	sp, sp, #20
+	cmp	r1, #0
+	mov	r12, r2
+	str	r1, [sp, #12]
+	str	r0, [sp, #16]
+	ldr	r2, [sp, #52]
+	beq	0f
+	lsl	r3, r3, #2
+	str	r3, [sp]
+	ldr	r3, [sp, #56]
+	mov	r10, #0
+	lsl	r3, r3, #2
+	str	r3, [sp, #8]
+	mov	r11, r3
+	b	1f
+6:	ldr	r11, [sp, #8]
+1:	ldr	r9, [sp]
+	mov	r0, r12
+	add	r12, r12, r9
+	mov	r1, r2
+	str	r12, [sp, #4]
+	add	r2, r2, r11
+	ldr	r12, [sp, #16]
+	ldr	r3, =0x00800080
+	ldr	r9, =0xff00ff00
+	mov	r11, #255
+	cmp	r12, #0
+	beq	4f
+5:	ldr	r5, [r1], #4
+	ldr	r4, [r0]
+	sub	r8, r11, r5, lsr #24
+	uxtb16	r6, r4
+	uxtb16	r7, r4, ror #8
+	mla	r6, r6, r8, r3
+	mla	r7, r7, r8, r3
+	uxtab16	r6, r6, r6, ror #8
+	uxtab16	r7, r7, r7, ror #8
+	and	r7, r7, r9
+	uxtab16	r6, r7, r6, ror #8
+	uqadd8	r5, r6, r5
+	str	r5, [r0], #4
+	subs	r12, r12, #1
+	bne	5b
+4:	ldr	r3, [sp, #12]
+	add	r10, r10, #1
+	cmp	r10, r3
+	ldr	r12, [sp, #4]
+	bne	6b
+0:	add	sp, sp, #20
+	pop	{r4, r5, r6, r7, r8, r9, r10, r11}
+	bx	lr
+.endfunc
+
+pixman_asm_function pixman_composite_over_8888_n_8888_asm_armv6
+	push	{r4, r5, r6, r7, r8, r9, r10, r11}
+	sub	sp, sp, #28
+	cmp	r1, #0
+	str	r1, [sp, #12]
+	ldrb	r1, [sp, #71]
+	mov	r12, r2
+	str	r0, [sp, #16]
+	ldr	r2, [sp, #60]
+	str	r1, [sp, #24]
+	beq	0f
+	lsl	r3, r3, #2
+	str	r3, [sp, #20]
+	ldr	r3, [sp, #64]
+	mov	r10, #0
+	lsl	r3, r3, #2
+	str	r3, [sp, #8]
+	mov	r11, r3
+	b	1f
+5:	ldr	r11, [sp, #8]
+1:	ldr	r4, [sp, #20]
+	mov	r0, r12
+	mov	r1, r2
+	add	r12, r12, r4
+	add	r2, r2, r11
+	str	r12, [sp]
+	str	r2, [sp, #4]
+	ldr	r12, [sp, #16]
+	ldr	r2, =0x00800080
+	ldr	r3, [sp, #24]
+	mov	r11, #255
+	cmp	r12, #0
+	beq	3f
+4:	ldr	r5, [r1], #4
+	ldr	r4, [r0]
+	uxtb16	r6, r5
+	uxtb16	r7, r5, ror #8
+	mla	r6, r6, r3, r2
+	mla	r7, r7, r3, r2
+	uxtab16	r6, r6, r6, ror #8
+	uxtab16	r7, r7, r7, ror #8
+	uxtb16	r6, r6, ror #8
+	uxtb16	r7, r7, ror #8
+	orr	r5, r6, r7, lsl #8
+	uxtb16	r6, r4
+	uxtb16	r7, r4, ror #8
+	sub	r8, r11, r5, lsr #24
+	mla	r6, r6, r8, r2
+	mla	r7, r7, r8, r2
+	uxtab16	r6, r6, r6, ror #8
+	uxtab16	r7, r7, r7, ror #8
+	uxtb16	r6, r6, ror #8
+	uxtb16	r7, r7, ror #8
+	orr	r6, r6, r7, lsl #8
+	uqadd8	r5, r6, r5
+	str	r5, [r0], #4
+	subs	r12, r12, #1
+	bne	4b
+3:	ldr	r1, [sp, #12]
+	add	r10, r10, #1
+	cmp	r10, r1
+	ldr	r12, [sp]
+	ldr	r2, [sp, #4]
+	bne	5b
+0:	add	sp, sp, #28
+	pop	{r4, r5, r6, r7, r8, r9, r10, r11}
+	bx	lr
+.endfunc
+
+pixman_asm_function pixman_composite_over_n_8_8888_asm_armv6
+	push	{r4, r5, r6, r7, r8, r9, r10, r11}
+	sub	sp, sp, #28
+	cmp	r1, #0
+	ldr	r9, [sp, #60]
+	str	r1, [sp, #12]
+	bic	r1, r9, #-16777216
+	str	r1, [sp, #20]
+	mov	r12, r2
+	lsr	r1, r9, #8
+	ldr	r2, [sp, #20]
+	bic	r1, r1, #-16777216
+	bic	r2, r2, #65280
+	bic	r1, r1, #65280
+	str	r2, [sp, #20]
+	str	r0, [sp, #16]
+	str	r1, [sp, #4]
+	ldr	r2, [sp, #68]
+	beq	0f
+	lsl	r3, r3, #2
+	str	r3, [sp, #24]
+	mov	r0, #0
+	b	1f
+5:	ldr	r3, [sp, #24]
+1:	ldr	r4, [sp, #72]
+	mov	r10, r12
+	mov	r1, r2
+	add	r12, r12, r3
+	add	r2, r2, r4
+	str	r12, [sp, #8]
+	str	r2, [sp]
+	ldr	r12, [sp, #16]
+	ldr	r11, =0x00800080
+	ldr	r2, [sp, #4]
+	ldr	r3, [sp, #20]
+	cmp	r12, #0
+	beq	3f
+4:	ldrb	r5, [r1], #1
+	ldr	r4, [r10]
+	mla	r6, r3, r5, r11
+	mla	r7, r2, r5, r11
+	uxtab16	r6, r6, r6, ror #8
+	uxtab16	r7, r7, r7, ror #8
+	uxtb16	r6, r6, ror #8
+	uxtb16	r7, r7, ror #8
+	orr	r5, r6, r7, lsl #8
+	uxtb16	r6, r4
+	uxtb16	r7, r4, ror #8
+	mvn	r8, r5
+	lsr	r8, r8, #24
+	mla	r6, r6, r8, r11
+	mla	r7, r7, r8, r11
+	uxtab16	r6, r6, r6, ror #8
+	uxtab16	r7, r7, r7, ror #8
+	uxtb16	r6, r6, ror #8
+	uxtb16	r7, r7, ror #8
+	orr	r6, r6, r7, lsl #8
+	uqadd8	r5, r6, r5
+	str	r5, [r10], #4
+	subs	r12, r12, #1
+	bne	4b
+3:	ldr	r4, [sp, #12]
+	add	r0, r0, #1
+	cmp	r0, r4
+	ldr	r12, [sp, #8]
+	ldr	r2, [sp]
+	bne	5b
+0:	add	sp, sp, #28
+	pop	{r4, r5, r6, r7, r8, r9, r10, r11}
+	bx	lr
+.endfunc
diff --git a/pixman/pixman-arm-simd.c b/pixman/pixman-arm-simd.c
index f110753..389c9e0 100644
--- a/pixman/pixman-arm-simd.c
+++ b/pixman/pixman-arm-simd.c
@@ -30,6 +30,8 @@
 #include "pixman-private.h"
 #include "pixman-arm-common.h"
 
+#if 0 /* This code was moved to 'pixman-arm-simd-asm.S' */
+
 void
 pixman_composite_add_8000_8000_asm_armv6 (int32_t  width,
                                           int32_t  height,
@@ -371,6 +373,8 @@ pixman_composite_over_n_8_8888_asm_armv6 (int32_t   width,
     }
 }
 
+#endif
+
 PIXMAN_ARM_BIND_FAST_PATH_SRC_DST (armv6, add_8000_8000,
                                    uint8_t, 1, uint8_t, 1)
 PIXMAN_ARM_BIND_FAST_PATH_SRC_DST (armv6, over_8888_8888,