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PATCH: Turn on x86_rep_movl_optimal for m_GENERIC64


On Fri, Nov 17, 2006 at 07:19:51AM -0800, H. J. Lu wrote:
> 
> I found the following on Core 2 Duo:
> 
> 1. The optimized memory functions don't help SPEC CPU 2K FP much.
> 2. The optimized memory functions help SPEC CPU 2K INT:
> 			-O2 + optimized memory vs -O2
> 164.gzip                         1.44928%
> 175.vpr                          -0.522952%
> 176.gcc                          23.6236%
> 181.mcf                          -1.30276%
> 186.crafty                       -0.576258%
> 197.parser                       0.64%
> 252.eon                          0.480769%
> 253.perlbmk                      -1.60281%
> 254.gap                          -0.406504%
> 255.vortex                       10.6028%
> 256.bzip2                        0.0993542%
> 300.twolf                        -0.0783392%
> Est. SPECint_base2000            2.457%
> 
> 3. rep_movl_optimal + optimized memory functions don't help SPEC CPU
> 2K FP much.
> 4. rep_movl_optimal + optimized memory functions is a mixed bag on
> SPEC CPU 2K INT:
> 
> 		-O2 + optimized memory + rep_movl_optimal vs -O2 + optimized memory
> 164.gzip                         0%
> 175.vpr                          -0.233645%
> 176.gcc                          -2.18623%
> 181.mcf                          1.10876%
> 186.crafty                       0.772798%
> 197.parser                       -0.317965%
> 252.eon                          -0.438596%
> 253.perlbmk                      1.58919%
> 254.gap                          0.272109%
> 255.vortex                       0.231929%
> 256.bzip2                        0%
> 300.twolf                        0.117601%
> Est. SPECint_base2000            0.0959233%
> 
> Given that rep_movl_optimal improves 176.gcc significantly with the
> old memory fuctions and doesn't have no significant negative impact
> with optimized memory functions, I think we should turn it on for
> m_GENERIC64. We can always fine tune rep_movl_optimal later.
> 
> 

Here is the patch.


H.J.
----
2006-11-17  H.J. Lu  <hongjiu.lu@intel.com>

	* config/i386/i386.c (x86_rep_movl_optimal): Turn it on for
	m_GENERIC64.

--- gcc/config/i386/i386.c.movl	2006-11-17 07:44:54.000000000 -0800
+++ gcc/config/i386/i386.c	2006-11-17 07:46:39.000000000 -0800
@@ -870,7 +870,7 @@ const int x86_sse_split_regs = m_ATHLON_
 const int x86_sse_typeless_stores = m_ATHLON_K8;
 const int x86_sse_load0_by_pxor = m_PPRO | m_PENT4 | m_NOCONA;
 const int x86_use_ffreep = m_ATHLON_K8;
-const int x86_rep_movl_optimal = m_386 | m_PENT | m_PPRO | m_K6_GEODE;
+const int x86_rep_movl_optimal = m_386 | m_PENT | m_PPRO | m_K6_GEODE | m_GENERIC64;
 const int x86_use_incdec = ~(m_PENT4 | m_NOCONA | m_GENERIC);
 
 /* ??? Allowing interunit moves makes it all too easy for the compiler to put


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