[PATCH] drm: sti: remove redundant sign extensions

From: Rasmus Villemoes
Date: Fri Oct 16 2015 - 09:15:25 EST


arg is long int, so arg = (arg << 22) >> 22 makes the upper 22 bits of
arg equal to bit 9 (or bit 41). But we then mask away all but bits 0-9, so
this is entirely redundant.

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
gcc seems to be smart enough to realize this - the generated code is
the same. This is thus just a tiny cleanup.

drivers/gpu/drm/sti/sti_awg_utils.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/gpu/drm/sti/sti_awg_utils.c b/drivers/gpu/drm/sti/sti_awg_utils.c
index 6029a2e3db1d..00d0698be9d3 100644
--- a/drivers/gpu/drm/sti/sti_awg_utils.c
+++ b/drivers/gpu/drm/sti/sti_awg_utils.c
@@ -65,7 +65,6 @@ static int awg_generate_instr(enum opcode opcode,

mux = 0;
data_enable = 0;
- arg = (arg << 22) >> 22;
arg &= (0x3ff);
break;
case REPEAT:
@@ -77,14 +76,12 @@ static int awg_generate_instr(enum opcode opcode,

mux = 0;
data_enable = 0;
- arg = (arg << 22) >> 22;
arg &= (0x3ff);
break;
case JUMP:
mux = 0;
data_enable = 0;
arg |= 0x40; /* for jump instruction 7th bit is 1 */
- arg = (arg << 22) >> 22;
arg &= 0x3ff;
break;
case STOP:
@@ -94,7 +91,6 @@ static int awg_generate_instr(enum opcode opcode,
case RPTSET:
case RPLSET:
case HOLD:
- arg = (arg << 24) >> 24;
arg &= (0x0ff);
break;
default:
--
2.6.1

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