X86: Shrink certain forms of movsx.

In particular:
movsbw %al, %ax   --> cbtw
movswl %ax, %eax  --> cwtl
movslq %eax, %rax --> cltq

According to Intel's manual those have the same performance characteristics but
come with a smaller encoding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186174 91177308-0d34-0410-b5e6-96231b3b80d8
Fixed comment in header of Block Frequency Impl and added text for C++ mode.

This is a generic block implementation that works on more than machine blocks.
The C++ mode addition is a bonus due to the extra space provided.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186175 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Add ISA documents to the CompilerWriterInfo page

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186176 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Add initial double precision support for SI

Patch by: Niels Ole Salscheider

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186177 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: SI support for 64bit ConstantFP

Patch by: Niels Ole Salscheider

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186178 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Add double precision fsub pattern for SI

Patch by: Niels Ole Salscheider

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186179 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Add fsqrt pattern for SI

Patch by: Niels Ole Salscheider

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186180 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Implement select and compares for SI

Patch by: Niels Ole Salscheider

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186181 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Add support for f64 kernel arguments

Patch by: Niels Ole Salscheider

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186182 91177308-0d34-0410-b5e6-96231b3b80d8
Add a test for the 'o' option in llvm-ar.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186183 91177308-0d34-0410-b5e6-96231b3b80d8
Relax test a bit to handle umask differences.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186184 91177308-0d34-0410-b5e6-96231b3b80d8