Make it possible to test the generated assembly

This test framework feature is inspired by a similar feature in LLVM.
The programmer writes a bit of Cmm

    #include "Cmm.h"

    // Large memcpy's should lower to calls.
    callMemcpy
    {
      W_ dst, src;
      prim %memcpy(dst "ptr", src "ptr", 1024, 4) [];
    }

and asserts what the generated assembly should look like, modulo
register naming.

    callMemcpy:
    movq  ; Move arguments into place
    movq
    movl
    movl
    call memcpy

Patch edited and updated by Simon Marlow, and I also added a test for
unrolling memcpy and a simple constant-propagation test.

9 files changed, 137 insertions, 1 deletions

diff --git a/testsuite/driver/testlib.py b/testsuite/driver/testlib.py
index 5853413871..4531801bb4 100644
--- a/testsuite/driver/testlib.py
+++ b/testsuite/driver/testlib.py
@@ -329,6 +329,12 @@ def if_arch( arch, f ):
     else:
         return normal
 
+def unless_arch( arch, f ):
+    if config.arch == arch:
+        return normal
+    else:
+        return f
+
 def if_wordsize( ws, f ):
     if config.wordsize == str(ws):
         return f
@@ -941,6 +947,33 @@ def do_compile( name, way, should_fail, top_mod, extra_mods, extra_hc_opts ):
     # no problems found, this test passed
     return passed()
 
+def compile_cmp_asm( name, way, extra_hc_opts ):
+    print 'Compile only, extra args = ', extra_hc_opts
+    pretest_cleanup(name)
+    result = simple_build( name + '.cmm', way, '-keep-s-files -O ' + extra_hc_opts, 0, '', 0, 0, 0)
+
+    if badResult(result):
+        return result
+
+    # the actual stderr should always match the expected, regardless
+    # of whether we expected the compilation to fail or not (successful
+    # compilations may generate warnings).
+
+    if getTestOpts().with_namebase == None:
+        namebase = name
+    else:
+        namebase = getTestOpts().with_namebase
+
+    (platform_specific, expected_asm_file) = platform_wordsize_qualify(namebase, 'asm')
+    actual_asm_file = qualify(name, 's')
+
+    if not compare_outputs('asm', two_normalisers(normalise_errmsg, normalise_asm), \
+                           expected_asm_file, actual_asm_file):
+        return failBecause('asm mismatch')
+
+    # no problems found, this test passed
+    return passed()
+
 # -----------------------------------------------------------------------------
 # Compile-and-run tests
 
@@ -1674,6 +1707,26 @@ def normalise_output( str ):
     str = re.sub('([^\\s])\\.exe', '\\1', str)
     return str
 
+def normalise_asm( str ):
+    lines = str.split('\n')
+    # Only keep instructions and labels not starting with a dot.
+    metadata = re.compile('^[ \t]*\\..*$')
+    out = []
+    for line in lines:
+      # Drop metadata directives (e.g. ".type")
+      if not metadata.match(line):
+        instr = line.lstrip().split()
+        # Drop empty lines.
+        if not instr:
+          continue
+        # Drop operands, except for call instructions.
+        elif instr[0] == 'call':
+          out.append(instr[0] + ' ' + instr[1])
+        else:
+          out.append(instr[0])
+    out = '\n'.join(out)
+    return out
+
 def if_verbose( n, str ):
     if config.verbose >= n:
         print str
@@ -2118,4 +2171,3 @@ def getStdout(cmd):
         return stdout
     else:
         raise Exception("Need subprocess to get stdout, but don't have it")
-
diff --git a/testsuite/tests/codeGen/should_gen_asm/Makefile b/testsuite/tests/codeGen/should_gen_asm/Makefile
new file mode 100644
index 0000000000..9101fbd40a
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/Makefile
@@ -0,0 +1,3 @@
+TOP=../../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/test.mk
diff --git a/testsuite/tests/codeGen/should_gen_asm/all.T b/testsuite/tests/codeGen/should_gen_asm/all.T
new file mode 100644
index 0000000000..c262255342
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/all.T
@@ -0,0 +1,3 @@
+test('memcpy', unless_arch('x86_64',skip), compile_cmp_asm, [''])
+test('memcpy-unroll', unless_arch('x86_64',skip), compile_cmp_asm, [''])
+test('memcpy-unroll-conprop', unless_arch('x86_64',skip), compile_cmp_asm, [''])
diff --git a/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll-conprop.asm b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll-conprop.asm
new file mode 100644
index 0000000000..1bafb34ce9
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll-conprop.asm
@@ -0,0 +1,21 @@
+.text
+	.align 8
+.globl callMemcpy
+.type callMemcpy, @object
+callMemcpy:
+.Lc8:
+	testq %rbx,%rbx
+	je .Lcb
+	movl 0(%r14),%eax
+	movl %eax,0(%rbx)
+	movl 4(%r14),%eax
+	movl %eax,4(%rbx)
+	movl 8(%r14),%eax
+	movl %eax,8(%rbx)
+	movl 12(%r14),%eax
+	movl %eax,12(%rbx)
+.Lcb:
+	jmp *(%rbp)
+	.size callMemcpy, .-callMemcpy
+.section .note.GNU-stack,"",@progbits
+.ident "GHC 7.7.20121009"
diff --git a/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll-conprop.cmm b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll-conprop.cmm
new file mode 100644
index 0000000000..be4883d34f
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll-conprop.cmm
@@ -0,0 +1,14 @@
+#include "Cmm.h"
+
+// Check that we propagate the constants into the branch
+callMemcpy (W_ dst, W_ src)
+{
+    W_ size;
+    W_ alig;
+    size = 16;
+    alig = 4;
+    if (dst != 0) {
+      prim %memcpy(dst, src, size, alig);
+    }
+    return ();
+}
diff --git a/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll.asm b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll.asm
new file mode 100644
index 0000000000..ffb27e70b7
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll.asm
@@ -0,0 +1,18 @@
+.text
+	.align 8
+.globl callMemcpy
+.type callMemcpy, @object
+callMemcpy:
+.Lc3:
+	movl 0(%r14),%eax
+	movl %eax,0(%rbx)
+	movl 4(%r14),%eax
+	movl %eax,4(%rbx)
+	movl 8(%r14),%eax
+	movl %eax,8(%rbx)
+	movl 12(%r14),%eax
+	movl %eax,12(%rbx)
+	jmp *(%rbp)
+	.size callMemcpy, .-callMemcpy
+.section .note.GNU-stack,"",@progbits
+.ident "GHC 7.7.20121009"
diff --git a/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll.cmm b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll.cmm
new file mode 100644
index 0000000000..95656b4410
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/memcpy-unroll.cmm
@@ -0,0 +1,8 @@
+#include "Cmm.h"
+
+// Small memcpies should unroll
+callMemcpy (W_ dst, W_ src)
+{
+  prim %memcpy(dst, src, 16, 4);
+  return ();
+}
diff --git a/testsuite/tests/codeGen/should_gen_asm/memcpy.asm b/testsuite/tests/codeGen/should_gen_asm/memcpy.asm
new file mode 100644
index 0000000000..1fb604fc43
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/memcpy.asm
@@ -0,0 +1,9 @@
+callMemcpy:
+        movq  ; Move arguments into place
+        movq
+        movl
+        subq
+        movl
+        call memcpy
+        addq
+        jmp
diff --git a/testsuite/tests/codeGen/should_gen_asm/memcpy.cmm b/testsuite/tests/codeGen/should_gen_asm/memcpy.cmm
new file mode 100644
index 0000000000..0ff16639ef
--- /dev/null
+++ b/testsuite/tests/codeGen/should_gen_asm/memcpy.cmm
@@ -0,0 +1,8 @@
+#include "Cmm.h"
+
+// Large memcpy's should lower to calls.
+callMemcpy (W_ dst, W_ src)
+{
+  prim %memcpy(dst, src, 1024, 4);
+  return ();
+}