remove SkFixedMul_arm()

The portable SkFixedMul_longlong (here now renamed SkFixedMul)
generates shorter, equivalent code,

from
   0:   fb81 0200       smull   r0, r2, r1, r0
   4:   ea4f 4010       mov.w   r0, r0, lsr #16
   8:   ea40 4002       orr.w   r0, r0, r2, lsl #16

to
   0:   fb81 0100       smull   r0, r1, r1, r0
   4:   0c00            lsrs    r0, r0, #16
   6:   ea40 4001       orr.w   r0, r0, r1, lsl #16

(Notice, 2 bytes saved.)

Change-Id: Icb0f7e6d4379086fc602f956a4beb1265a9759bc
Reviewed-on: https://skia-review.googlesource.com/69440
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/include/private/SkFixed.h b/include/private/SkFixed.h
index 5cd811b..223df11 100644
--- a/include/private/SkFixed.h
+++ b/include/private/SkFixed.h
@@ -86,13 +86,12 @@
 #define SkFixedDiv(numer, denom) \
     SkToS32(SkTPin<int64_t>((SkLeftShift((int64_t)(numer), 16) / (denom)), SK_MinS32, SK_MaxS32))
 
-//////////////////////////////////////////////////////////////////////////////////////////////////////
-// Now look for ASM overrides for our portable versions (should consider putting this in its own file)
-
-inline SkFixed SkFixedMul_longlong(SkFixed a, SkFixed b) {
+static inline SkFixed SkFixedMul(SkFixed a, SkFixed b) {
     return (SkFixed)((int64_t)a * b >> 16);
 }
-#define SkFixedMul(a,b)     SkFixedMul_longlong(a,b)
+
+///////////////////////////////////////////////////////////////////////////////
+// Platform-specific alternatives to our portable versions.
 
 // The VCVT float-to-fixed instruction is part of the VFPv3 instruction set.
 #if defined(__ARM_VFPV3__)
@@ -111,23 +110,6 @@
     #define SkFloatToFixed(x)  SkFloatToFixed_arm(x)
 #endif
 
-#if defined(SK_CPU_ARM32)
-    inline SkFixed SkFixedMul_arm(SkFixed x, SkFixed y)
-    {
-        int32_t t;
-        asm("smull  %0, %2, %1, %3          \n"
-            "mov    %0, %0, lsr #16         \n"
-            "orr    %0, %0, %2, lsl #16     \n"
-            : "=r"(x), "=&r"(y), "=r"(t)
-            : "r"(x), "1"(y)
-            :
-            );
-        return x;
-    }
-    #undef SkFixedMul
-    #define SkFixedMul(x, y)        SkFixedMul_arm(x, y)
-#endif
-
 ///////////////////////////////////////////////////////////////////////////////
 
 #define SkFixedToScalar(x)          SkFixedToFloat(x)