Added information on input and output filenames.

Added periods to the end of sentence fragments describing options.
Added information to llc about which target architecture is selected for
assembly language code generation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8741 91177308-0d34-0410-b5e6-96231b3b80d8

docs/CommandGuide/llc.html

@@ -20,7 +20,7 @@ llc
 SYNOPSIS
 </h3>
 
-llc [options] &lt; filename&gt;
+llc [options] [filename]
 <h3>
 DESCRIPTION
 </h3>
@@ -28,6 +28,62 @@ DESCRIPTION
 The llc command compiles LLVM bytecode into assembly language for a specified
 architecture.  The assembly language output can then be passed through a native
 assembler and linker to generate native code.
+<p>
+The choice of architecture for the output assembly code is determined as
+follows:
+
+<ul>
+	<li>
+	If the user has specified an architecture with the -m option, use that
+	architecture.
+	<p>
+
+	<li>
+	Examine the input LLVM bytecode file:
+	<ul>
+		<li>
+		If it specifies little endian and a pointer size of 32 bits, select the
+		x86 architecture.
+		<p>
+		
+		<li>
+		If it specifies big endian and a pointer size of 64 bit pointers,
+		select the SparcV9 architecture.
+	</ul>
+	<p>
+
+	<li>
+	If llc was compiled on an architecture for which it can generate code,
+	select the architecture upon which llc was compiled.
+	<p>
+
+	<li>
+	Print a message to the user asking him or her to specify the output
+	architecture explicitly.
+</ul>
+
+<p>
+
+If filename is not specified, or if filename is -, llc reads its input from
+standard input.  Otherwise, it will read its input from filename.
+<p>
+
+If the -o option is left unspecified, then llc will send its output to standard
+output if the input is from standard input.  If the -o option specifies -, then
+the output will also be sent to standard output.
+<p>
+
+If no -o option is specified and an input file other than - is specified, then
+llc creates the output filename as follows:
+
+<ul>
+	<li>
+	If the file ends in .bc, then the .bc suffix is removed, and the .s suffix
+	is appended.
+	<p>
+	<li>
+	Otherwise, the .s suffix is appended to the input filename.
+</ul>
 
 <h3>
 OPTIONS
@@ -36,42 +92,42 @@ OPTIONS
 <ul>
 	<li>-disable-fp-elim     
 	<br>
-	Disable frame pointer elimination optimization
+	Disable frame pointer elimination optimization.
 	<p>
 
 	<li>-disable-local-ra    
 	<br>
-	Use Simple RA instead of Local RegAlloc
+	Use Simple RA instead of Local RegAlloc.
 	<p>
 
 	<li>-disable-pattern-isel
 	<br>
-	Use the 'simple' X86 instruction selector
+	Use the 'simple' X86 instruction selector.
 	<p>
 
 	<li>-disable-peephole    
 	<br>
-	Disable peephole optimization pass
+	Disable peephole optimization pass.
 	<p>
 
 	<li>-disable-preopt      
 	<br>
-	Disable optimizations prior to instruction selection
+	Disable optimizations prior to instruction selection.
 	<p>
 
 	<li>-disable-sched       
 	<br>
-	Disable local scheduling pass
+	Disable local scheduling pass.
 	<p>
 
 	<li>-disable-strip       
 	<br>
-	Do not strip the LLVM bytecode included in executable
+	Do not strip the LLVM bytecode included in executable.
 	<p>
 
 	<li>-enable-maps         
 	<br>
-	Emit LLVM-to-MachineCode mapping info to assembly
+	Emit LLVM-to-MachineCode mapping info to assembly.
 	<p>
 
 	<li>-f                   
@@ -81,13 +137,12 @@ OPTIONS
 
 	<li>-load=&lt;plugin.so&gt;
 	<br>
-	Load the specified plugin
+	Load the specified plugin.
 	<p>
 
 	<li>-m&lt;arch&gt;
 	<br>
 	Specify the architecture for which to generate assembly.  Valid
-	<p>
 	architectures are:
 
 	<dl compact>
@@ -103,12 +158,12 @@ OPTIONS
 
 	<li>-o &lt;filename&gt;
 	<br>
-	Output filename
+	Specify the output filename.
 	<p>
 
 	<li>-print-machineinstrs 
 	<br>
-	Print generated machine code
+	Print generated machine code.
 	<p>
 
 	<li> -help