<p>A powerful feature of the RUN: lines is that it allows any arbitrary commands
to be executed as part of the test harness. While standard (portable) unix
tools like 'grep' work fine on run lines, as you see above, there are a lot
- of caveats due to interaction with Tcl syntax, and we want to make that the
+ of caveats due to interaction with Tcl syntax, and we want to make sure the
run lines are portable to a wide range of systems. Another major problem is
that grep is not very good at checking to verify that the output of a tools
contains a series of different output in a specific order. The FileCheck
tool was designed to help with these problems.</p>
+<p>FileCheck (whose basic command line arguments are described in <a
+ href="http://llvm.org/cmds/FileCheck.html">the FileCheck man page</a> is
+ designed to read a file to check from standard input, and the set of things
+ to verify from a file specified as a command line argument. A simple example
+ of using FileCheck from a RUN line looks like this:</p>
+
+<div class="doc_code">
+<pre>
+; RUN: llvm-as < %s | llc -march=x86-64 | <b>FileCheck %s</b>
+</pre>
+</div>
-<!-- http://llvm.org/cmds/FileCheck.html -->
+<p>This syntax says to pipe the current file ("%s") into llvm-as, pipe that into
+llc, then pipe the output of llc into FileCheck. This means that FileCheck will
+be verifying its standard input (the llc output) against the filename argument
+specified (the original .ll file specified by "%s"). To see how this works,
+lets look at the rest of the .ll file (after the RUN line):</p>
+
+<div class="doc_code">
+<pre>
+define void @sub1(i32* %p, i32 %v) {
+entry:
+; <b>CHECK: sub1:</b>
+; <b>CHECK: subl</b>
+ %0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v)
+ ret void
+}
+
+define void @inc4(i64* %p) {
+entry:
+; <b>CHECK: inc4:</b>
+; <b>CHECK: incq</b>
+ %0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1)
+ ret void
+}
+</pre>
+</div>
+
+<p>Here you can see some "CHECK:" lines specified in comments. Now you can see
+how the file is piped into llvm-as, then llc, and the machine code output is
+what we are verifying. FileCheck checks the machine code output to verify that
+it matches what the "CHECK:" lines specify.</p>
+
+<p>The syntax of the CHECK: lines is very simple: they are fixed strings that
+must occur in order. FileCheck defaults to ignoring horizontal whitespace
+differences (e.g. a space is allowed to match a tab) but otherwise, the contents
+of the CHECK: line is required to match some thing in the test file exactly.</p>
+
+<p>One nice thing about FileCheck (compared to grep) is that it allows merging
+test cases together into logical groups. For example, because the test above
+is checking for the "sub1:" and "inc4:" labels, it will not match unless there
+is a "subl" in between those labels. If it existed somewhere else in the file,
+that would not count: "grep subl" matches if subl exists anywhere in the
+file.</p>
</div>
<!-- _______________________________________________________________________ -->
-<div class="doc_subsection"><a name="dgvars">Variables and substitutions</a></div>
+<div class="doc_subsubsection"><a
+name="FileCheck-check-prefix">The FileCheck -check-prefix option</a></div>
+
+<div class="doc_text">
+
+<p>The FileCheck -check-prefix option allows multiple test configurations to be
+driven from one .ll file. This is useful in many circumstances, for example,
+testing different architectural variants with llc. Here's a simple example:</p>
+
+<div class="doc_code">
+<pre>
+; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \
+; RUN: | <b>FileCheck %s -check-prefix=X32</b>
+; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \
+; RUN: | <b>FileCheck %s -check-prefix=X64</b>
+
+define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind {
+ %tmp1 = insertelement <4 x i32> %tmp, i32 %s, i32 1
+ ret <4 x i32> %tmp1
+; <b>X32:</b> pinsrd_1:
+; <b>X32:</b> pinsrd $1, 4(%esp), %xmm0
+
+; <b>X64:</b> pinsrd_1:
+; <b>X64:</b> pinsrd $1, %edi, %xmm0
+}
+</pre>
+</div>
+
+<p>In this case, we're testing that we get the expected code generation with
+both 32-bit and 64-bit code generation.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"><a
+name="FileCheck-CHECK-NEXT">The "CHECK-NEXT:" directive</a></div>
+
+<div class="doc_text">
+
+<p>Sometimes you want to match lines and would like to verify that matches
+happen on exactly consequtive lines with no other lines in between them. In
+this case, you can use CHECK: and CHECK-NEXT: directives to specify this. If
+you specified a custom check prefix, just use "<PREFIX>-NEXT:". For
+example, something like this works as you'd expect:</p>
+
+<div class="doc_code">
+<pre>
+define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) {
+ %tmp3 = load <2 x double>* %A, align 16
+ %tmp7 = insertelement <2 x double> undef, double %B, i32 0
+ %tmp9 = shufflevector <2 x double> %tmp3,
+ <2 x double> %tmp7,
+ <2 x i32> < i32 0, i32 2 >
+ store <2 x double> %tmp9, <2 x double>* %r, align 16
+ ret void
+
+; <b>CHECK:</b> t2:
+; <b>CHECK:</b> movl 8(%esp), %eax
+; <b>CHECK-NEXT:</b> movapd (%eax), %xmm0
+; <b>CHECK-NEXT:</b> movhpd 12(%esp), %xmm0
+; <b>CHECK-NEXT:</b> movl 4(%esp), %eax
+; <b>CHECK-NEXT:</b> movapd %xmm0, (%eax)
+; <b>CHECK-NEXT:</b> ret
+}
+</pre>
+</div>
+
+<p>CHECK-NEXT: directives reject the input unless there is exactly one newline
+between it an the previous directive. A CHECK-NEXT cannot be the first
+directive in a file.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"><a
+name="FileCheck-CHECK-NOT">The "CHECK-NOT:" directive</a></div>
+
+<div class="doc_text">
+
+<p>The CHECK-NOT: directive is used to verify that a string doesn't occur
+between two matches (or the first match and the beginning of the file). For
+example, to verify that a load is removed by a transformation, a test like this
+can be used:</p>
+
+<div class="doc_code">
+<pre>
+define i8 @coerce_offset0(i32 %V, i32* %P) {
+ store i32 %V, i32* %P
+
+ %P2 = bitcast i32* %P to i8*
+ %P3 = getelementptr i8* %P2, i32 2
+
+ %A = load i8* %P3
+ ret i8 %A
+; <b>CHECK:</b> @coerce_offset0
+; <b>CHECK-NOT:</b> load
+; <b>CHECK:</b> ret i8
+}
+</pre>
+</div>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"><a
+name="FileCheck-Matching">FileCheck Pattern Matching Syntax</a></div>
+
+<div class="doc_text">
+
+<p>The CHECK: and CHECK-NOT: directives both take a pattern to match. For most
+uses of FileCheck, fixed string matching is perfectly sufficient. For some
+things, a more flexible form of matching is desired. To support this, FileCheck
+allows you to specify regular expressions in matching strings, surrounded by
+double braces: <b>{{yourregex}}</b>. Because we want to use fixed string
+matching for a majority of what we do, FileCheck has been designed to support
+mixing and matching fixed string matching with regular expressions. This allows
+you to write things like this:</p>
+
+<div class="doc_code">
+<pre>
+; CHECK: movhpd <b>{{[0-9]+}}</b>(%esp), <b>{{%xmm[0-7]}}</b>
+</pre>
+</div>
+
+<p>In this case, any offset from the ESP register will be allowed, and any xmm
+register will be allowed.</p>
+
+<p>Because regular expressions are enclosed with double braces, they are
+visually distinct, and you don't need to use escape characters within the double
+braces like you would in C. In the rare case that you want to match double
+braces explicitly from the input, you can use something ugly like
+<b>{{[{][{]}}</b> as your pattern.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"><a
+name="FileCheck-Variables">FileCheck Variables</a></div>
+
+<div class="doc_text">
+
+<p>It is often useful to match a pattern and then verify that it occurs again
+later in the file. For codegen tests, this can be useful to allow any register,
+but verify that that register is used consistently later. To do this, FileCheck
+allows named variables to be defined and substituted into patterns. Here is a
+simple example:</p>
+
+<div class="doc_code">
+<pre>
+; CHECK: test5:
+; CHECK: notw <b>[[REGISTER:%[a-z]+]]</b>
+; CHECK: andw {{.*}}<b>[[REGISTER]]</b>
+</pre>
+</div>
+
+<p>The first check line matches a regex (<tt>%[a-z]+</tt>) and captures it into
+the variables "REGISTER". The second line verifies that whatever is in REGISTER
+occurs later in the file after an "andw". FileCheck variable references are
+always contained in <tt>[[ ]]</tt> pairs, are named, and their names can be
+formed with the regex "<tt>[a-zA-Z][a-zA-Z0-9]*</tt>". If a colon follows the
+name, then it is a definition of the variable, if not, it is a use.</p>
+
+<p>FileCheck variables can be defined multiple times, and uses always get the
+latest value. Note that variables are all read at the start of a "CHECK" line
+and are all defined at the end. This means that if you have something like
+"<tt>CHECK: [[XYZ:.*]]x[[XYZ]]</tt>" that the check line will read the previous
+value of the XYZ variable and define a new one after the match is performed. If
+you need to do something like this you can probably take advantage of the fact
+that FileCheck is not actually line-oriented when it matches, this allows you to
+define two separate CHECK lines that match on the same line.
+</p>
+
+
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsection"><a name="dgvars">Variables and
+substitutions</a></div>
<!-- _______________________________________________________________________ -->
<div class="doc_text">
<p>With a RUN line there are a number of substitutions that are permitted. In
<dd>The target triplet that corresponds to the current host machine (the one
running the test cases). This should probably be called "host".<dd>
- <dt><b>prcontext</b> (%prcontext)</dt>
- <dd>Path to the prcontext tcl script that prints some context around a
- line that matches a pattern. This isn't strictly necessary as the test suite
- is run with its PATH altered to include the test/Scripts directory where
- the prcontext script is located. Note that this script is similar to
- <tt>grep -C</tt> but you should use the <tt>prcontext</tt> script because
- not all platforms support <tt>grep -C</tt>.</dd>
-
<dt><b>llvmgcc</b> (%llvmgcc)</dt>
<dd>The full path to the <tt>llvm-gcc</tt> executable as specified in the
configured LLVM environment</dd>
projects / oota-llvm.git / blobdiff