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			291 lines
		
	
	
		
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			ReStructuredText
		
	
	
	
	
	
			
		
		
	
	
			291 lines
		
	
	
		
			9.2 KiB
		
	
	
	
		
			ReStructuredText
		
	
	
	
	
	
| FileCheck - Flexible pattern matching file verifier
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| ===================================================
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| 
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| 
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| SYNOPSIS
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| --------
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| 
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| 
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| **FileCheck** *match-filename* [*--check-prefix=XXX*] [*--strict-whitespace*]
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| 
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| 
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| DESCRIPTION
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| -----------
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| 
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| 
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| **FileCheck** reads two files (one from standard input, and one specified on the
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| command line) and uses one to verify the other.  This behavior is particularly
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| useful for the testsuite, which wants to verify that the output of some tool
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| (e.g. llc) contains the expected information (for example, a movsd from esp or
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| whatever is interesting).  This is similar to using grep, but it is optimized
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| for matching multiple different inputs in one file in a specific order.
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| 
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| The *match-filename* file specifies the file that contains the patterns to
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| match.  The file to verify is always read from standard input.
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| 
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| 
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| OPTIONS
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| -------
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| 
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| 
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| 
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| **-help**
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| 
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|  Print a summary of command line options.
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| 
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| 
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| 
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| **--check-prefix** *prefix*
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| 
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|  FileCheck searches the contents of *match-filename* for patterns to match.  By
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|  default, these patterns are prefixed with "CHECK:".  If you'd like to use a
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|  different prefix (e.g. because the same input file is checking multiple
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|  different tool or options), the **--check-prefix** argument allows you to specify
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|  a specific prefix to match.
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| 
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| 
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| 
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| **--input-file** *filename*
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| 
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|   File to check (defaults to stdin).
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| 
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| 
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| **--strict-whitespace**
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| 
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|  By default, FileCheck canonicalizes input horizontal whitespace (spaces and
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|  tabs) which causes it to ignore these differences (a space will match a tab).
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|  The --strict-whitespace argument disables this behavior.
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| 
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| 
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| 
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| **-version**
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| 
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|  Show the version number of this program.
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| 
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| 
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| 
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| 
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| EXIT STATUS
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| -----------
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| 
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| 
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| If **FileCheck** verifies that the file matches the expected contents, it exits
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| with 0.  Otherwise, if not, or if an error occurs, it will exit with a non-zero
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| value.
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| 
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| 
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| TUTORIAL
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| --------
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| 
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| 
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| FileCheck is typically used from LLVM regression tests, being invoked on the RUN
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| line of the test.  A simple example of using FileCheck from a RUN line looks
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| like this:
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| 
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| 
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| .. code-block:: llvm
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| 
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|    ; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s
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| 
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| 
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| This syntax says to pipe the current file ("%s") into llvm-as, pipe that into
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| llc, then pipe the output of llc into FileCheck.  This means that FileCheck will
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| be verifying its standard input (the llc output) against the filename argument
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| specified (the original .ll file specified by "%s").  To see how this works,
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| let's look at the rest of the .ll file (after the RUN line):
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| 
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| 
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| .. code-block:: llvm
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| 
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|    define void @sub1(i32* %p, i32 %v) {
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|    entry:
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|    ; CHECK: sub1:
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|    ; CHECK: subl
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|            %0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v)
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|            ret void
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|    }
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| 
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|    define void @inc4(i64* %p) {
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|    entry:
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|    ; CHECK: inc4:
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|    ; CHECK: incq
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|            %0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1)
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|            ret void
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|    }
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| 
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| 
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| Here you can see some "CHECK:" lines specified in comments.  Now you can see
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| how the file is piped into llvm-as, then llc, and the machine code output is
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| what we are verifying.  FileCheck checks the machine code output to verify that
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| it matches what the "CHECK:" lines specify.
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| 
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| The syntax of the CHECK: lines is very simple: they are fixed strings that
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| must occur in order.  FileCheck defaults to ignoring horizontal whitespace
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| differences (e.g. a space is allowed to match a tab) but otherwise, the contents
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| of the CHECK: line is required to match some thing in the test file exactly.
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| 
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| One nice thing about FileCheck (compared to grep) is that it allows merging
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| test cases together into logical groups.  For example, because the test above
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| is checking for the "sub1:" and "inc4:" labels, it will not match unless there
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| is a "subl" in between those labels.  If it existed somewhere else in the file,
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| that would not count: "grep subl" matches if subl exists anywhere in the
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| file.
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| 
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| The FileCheck -check-prefix option
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| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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| 
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| 
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| The FileCheck -check-prefix option allows multiple test configurations to be
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| driven from one .ll file.  This is useful in many circumstances, for example,
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| testing different architectural variants with llc.  Here's a simple example:
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| 
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| 
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| .. code-block:: llvm
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| 
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|    ; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \
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|    ; RUN:              | FileCheck %s -check-prefix=X32
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|    ; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \
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|    ; RUN:              | FileCheck %s -check-prefix=X64
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| 
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|    define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind {
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|            %tmp1 = insertelement <4 x i32>; %tmp, i32 %s, i32 1
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|            ret <4 x i32> %tmp1
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|    ; X32: pinsrd_1:
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|    ; X32:    pinsrd $1, 4(%esp), %xmm0
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| 
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|    ; X64: pinsrd_1:
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|    ; X64:    pinsrd $1, %edi, %xmm0
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|    }
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| 
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| 
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| In this case, we're testing that we get the expected code generation with
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| both 32-bit and 64-bit code generation.
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| 
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| 
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| The "CHECK-NEXT:" directive
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| ~~~~~~~~~~~~~~~~~~~~~~~~~~~
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| 
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| 
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| Sometimes you want to match lines and would like to verify that matches
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| happen on exactly consecutive lines with no other lines in between them.  In
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| this case, you can use CHECK: and CHECK-NEXT: directives to specify this.  If
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| you specified a custom check prefix, just use "<PREFIX>-NEXT:".  For
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| example, something like this works as you'd expect:
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| 
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| 
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| .. code-block:: llvm
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| 
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|    define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) {
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|  	%tmp3 = load <2 x double>* %A, align 16
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|  	%tmp7 = insertelement <2 x double> undef, double %B, i32 0
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|  	%tmp9 = shufflevector <2 x double> %tmp3,
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|                                <2 x double> %tmp7,
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|                                <2 x i32> < i32 0, i32 2 >
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|  	store <2 x double> %tmp9, <2 x double>* %r, align 16
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|  	ret void
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| 
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|    ; CHECK:          t2:
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|    ; CHECK: 	        movl	8(%esp), %eax
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|    ; CHECK-NEXT: 	movapd	(%eax), %xmm0
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|    ; CHECK-NEXT: 	movhpd	12(%esp), %xmm0
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|    ; CHECK-NEXT: 	movl	4(%esp), %eax
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|    ; CHECK-NEXT: 	movapd	%xmm0, (%eax)
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|    ; CHECK-NEXT: 	ret
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|    }
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| 
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| 
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| CHECK-NEXT: directives reject the input unless there is exactly one newline
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| between it an the previous directive.  A CHECK-NEXT cannot be the first
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| directive in a file.
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| 
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| 
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| The "CHECK-NOT:" directive
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| ~~~~~~~~~~~~~~~~~~~~~~~~~~
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| 
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| 
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| The CHECK-NOT: directive is used to verify that a string doesn't occur
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| between two matches (or before the first match, or after the last match).  For
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| example, to verify that a load is removed by a transformation, a test like this
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| can be used:
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| 
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| 
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| .. code-block:: llvm
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| 
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|    define i8 @coerce_offset0(i32 %V, i32* %P) {
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|      store i32 %V, i32* %P
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| 
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|      %P2 = bitcast i32* %P to i8*
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|      %P3 = getelementptr i8* %P2, i32 2
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| 
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|      %A = load i8* %P3
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|      ret i8 %A
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|    ; CHECK: @coerce_offset0
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|    ; CHECK-NOT: load
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|    ; CHECK: ret i8
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|    }
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| 
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| 
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| 
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| FileCheck Pattern Matching Syntax
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| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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| 
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| 
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| The CHECK: and CHECK-NOT: directives both take a pattern to match.  For most
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| uses of FileCheck, fixed string matching is perfectly sufficient.  For some
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| things, a more flexible form of matching is desired.  To support this, FileCheck
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| allows you to specify regular expressions in matching strings, surrounded by
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| double braces: **{{yourregex}}**.  Because we want to use fixed string
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| matching for a majority of what we do, FileCheck has been designed to support
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| mixing and matching fixed string matching with regular expressions.  This allows
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| you to write things like this:
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| 
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| 
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| .. code-block:: llvm
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| 
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|    ; CHECK: movhpd	{{[0-9]+}}(%esp), {{%xmm[0-7]}}
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| 
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| 
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| In this case, any offset from the ESP register will be allowed, and any xmm
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| register will be allowed.
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| 
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| Because regular expressions are enclosed with double braces, they are
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| visually distinct, and you don't need to use escape characters within the double
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| braces like you would in C.  In the rare case that you want to match double
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| braces explicitly from the input, you can use something ugly like
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| **{{[{][{]}}** as your pattern.
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| 
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| 
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| FileCheck Variables
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| ~~~~~~~~~~~~~~~~~~~
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| 
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| 
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| It is often useful to match a pattern and then verify that it occurs again
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| later in the file.  For codegen tests, this can be useful to allow any register,
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| but verify that that register is used consistently later.  To do this, FileCheck
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| allows named variables to be defined and substituted into patterns.  Here is a
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| simple example:
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| 
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| 
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| .. code-block:: llvm
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| 
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|    ; CHECK: test5:
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|    ; CHECK:    notw	[[REGISTER:%[a-z]+]]
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|    ; CHECK:    andw	{{.*}}[[REGISTER]]
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| 
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| 
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| The first check line matches a regex (**%[a-z]+**) and captures it into
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| the variable "REGISTER".  The second line verifies that whatever is in REGISTER
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| occurs later in the file after an "andw".  FileCheck variable references are
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| always contained in **[[ ]]** pairs, and their names can be formed with the
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| regex **[a-zA-Z][a-zA-Z0-9]***.  If a colon follows the name, then it is a
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| definition of the variable; otherwise, it is a use.
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| 
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| FileCheck variables can be defined multiple times, and uses always get the
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| latest value.  Note that variables are all read at the start of a "CHECK" line
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| and are all defined at the end.  This means that if you have something like
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| "**CHECK: [[XYZ:.\\*]]x[[XYZ]]**", the check line will read the previous
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| value of the XYZ variable and define a new one after the match is performed.  If
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| you need to do something like this you can probably take advantage of the fact
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| that FileCheck is not actually line-oriented when it matches, this allows you to
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| define two separate CHECK lines that match on the same line.
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