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Commit 438a76167959061e371025f727fabec2ad9e70a7

Authored by Russell King
Committed by Russell King
1 parent b3402cf50e
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

[PATCH] ARM: Fix VFP to use do_div() 

VFP used __divdi3 64-bit division needlessly.  Convert it to use
our 64-bit by 32-bit division instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Showing 3 changed files with 27 additions and 4 deletions Side-by-side Diff

... ... @@ -117,7 +117,13 @@
117 117 if (nh >= m)
118 118 return ~0ULL;
119 119 mh = m >> 32;
120   - z = (mh << 32 <= nh) ? 0xffffffff00000000ULL : (nh / mh) << 32;
  120 + if (mh << 32 <= nh) {
  121 + z = 0xffffffff00000000ULL;
  122 + } else {
  123 + z = nh;
  124 + do_div(z, mh);
  125 + z <<= 32;
  126 + }
121 127 mul64to128(&termh, &terml, m, z);
122 128 sub128(&remh, &reml, nh, nl, termh, terml);
123 129 ml = m << 32;
... ... @@ -126,7 +132,12 @@
126 132 add128(&remh, &reml, remh, reml, mh, ml);
127 133 }
128 134 remh = (remh << 32) | (reml >> 32);
129   - z |= (mh << 32 <= remh) ? 0xffffffff : remh / mh;
  135 + if (mh << 32 <= remh) {
  136 + z |= 0xffffffff;
  137 + } else {
  138 + do_div(remh, mh);
  139 + z |= remh;
  140 + }
130 141 return z;
131 142 }
132 143  
arch/arm/vfp/vfpdouble.c
Diff comments   View file @ 438a761
... ... @@ -32,6 +32,8 @@
32 32 */
33 33 #include <linux/kernel.h>
34 34 #include <linux/bitops.h>
  35 +
  36 +#include <asm/div64.h>
35 37 #include <asm/ptrace.h>
36 38 #include <asm/vfp.h>
37 39  
arch/arm/vfp/vfpsingle.c
Diff comments   View file @ 438a761
... ... @@ -32,6 +32,8 @@
32 32 */
33 33 #include <linux/kernel.h>
34 34 #include <linux/bitops.h>
  35 +
  36 +#include <asm/div64.h>
35 37 #include <asm/ptrace.h>
36 38 #include <asm/vfp.h>
37 39  
... ... @@ -303,7 +305,11 @@
303 305 if (z <= a)
304 306 return (s32)a >> 1;
305 307 }
306   - return (u32)(((u64)a << 31) / z) + (z >> 1);
  308 + {
  309 + u64 v = (u64)a << 31;
  310 + do_div(v, z);
  311 + return v + (z >> 1);
  312 + }
307 313 }
308 314  
309 315 static u32 vfp_single_fsqrt(int sd, int unused, s32 m, u32 fpscr)
... ... @@ -1107,7 +1113,11 @@
1107 1113 vsn.significand >>= 1;
1108 1114 vsd.exponent++;
1109 1115 }
1110   - vsd.significand = ((u64)vsn.significand << 32) / vsm.significand;
  1116 + {
  1117 + u64 significand = (u64)vsn.significand << 32;
  1118 + do_div(significand, vsm.significand);
  1119 + vsd.significand = significand;
  1120 + }
1111 1121 if ((vsd.significand & 0x3f) == 0)
1112 1122 vsd.significand |= ((u64)vsm.significand * vsd.significand != (u64)vsn.significand << 32);
1113 1123