From 1541c313a08b1674a8a0603146697bee21429839 Mon Sep 17 00:00:00 2001
From: Andrew Mahone <andrew.mahone@gmail.com>
Date: Wed, 8 Apr 2009 06:25:06 +0000
Subject: Improve scaler reciprocal precision by 1 bit, and remove unused
 SC_NUM, SC_FIX, and SC_SHIFT.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20654 a1c6a512-1295-4272-9138-f99709370657
---
 apps/recorder/resize.c |  4 ++--
 apps/recorder/resize.h | 21 ---------------------
 2 files changed, 2 insertions(+), 23 deletions(-)

(limited to 'apps')

diff --git a/apps/recorder/resize.c b/apps/recorder/resize.c
index e75638140b..79be59804a 100644
--- a/apps/recorder/resize.c
+++ b/apps/recorder/resize.c
@@ -253,7 +253,7 @@ static inline bool scale_v_area(struct rowset *rset, struct scaler_context *ctx)
     /* Set up rounding and scale factors */
     ctx->divisor *= ctx->src->height;
     ctx->round = ctx->divisor >> 1;
-    ctx->divisor = (((ctx->divisor >> 1) + SC_NUM) / ctx->divisor) << SC_FIX;
+    ctx->divisor = 1 + (-((ctx->divisor + 1) >> 1)) / ctx->divisor;
     mul = 0;
     oy = rset->rowstart;
     oye = 0;
@@ -451,7 +451,7 @@ static inline bool scale_v_linear(struct rowset *rset,
     /* Set up scale and rounding factors, the divisor is bm->height - 1 */
     ctx->divisor *= (ctx->bm->height - 1);
     ctx->round = ctx->divisor >> 1;
-    ctx->divisor = (((ctx->divisor >> 1) + SC_NUM) / ctx->divisor) << SC_FIX;
+    ctx->divisor = 1 + (-((ctx->divisor + 1) >> 1)) / ctx->divisor;
     /* Set up our two temp buffers. The names are generic because they'll be
        swapped each time a new input row is read
     */
diff --git a/apps/recorder/resize.h b/apps/recorder/resize.h
index 4ea4eaa9a0..dc93585a08 100644
--- a/apps/recorder/resize.h
+++ b/apps/recorder/resize.h
@@ -44,7 +44,6 @@
 #define HAVE_UPSCALER 1
 
 #if defined(CPU_COLDFIRE)
-#define SC_NUM 0x80000000U
 #define SC_MUL_INIT \
     unsigned long macsr_st = coldfire_get_macsr(); \
     coldfire_set_macsr(EMAC_UNSIGNED);
@@ -101,32 +100,12 @@ static inline unsigned sc_mul32(unsigned a, unsigned b)
 #define SC_MUL_END
 #endif
 
-#ifndef SC_SHIFT
-#define SC_SHIFT 32
-#endif
-
-#if SC_SHIFT == 24
-#define SC_NUM 0x1000000U
-#define SC_FIX 0
-
-#ifndef SC_MUL
-#define SC_MUL(x, y) ((x) * (y) >> 24)
-#define SC_MUL_INIT
-#define SC_MUL_END
-#endif
-
-#else /* SC_SHIFT == 32 */
-#define SC_NUM 0x80000000U
-#define SC_FIX 1
-
 #ifndef SC_MUL
 #define SC_MUL(x, y) ((x) * (uint64_t)(y) >> 32)
 #define SC_MUL_INIT
 #define SC_MUL_END
 #endif
 
-#endif
-
 struct img_part {
     int len;
 #if !defined(HAVE_LCD_COLOR)    
-- 
cgit