m-labs · Dec 28, 2015 · Dec 28, 2015 · Dec 28, 2015
Showing with 32 additions and 4 deletions.

+2 −0 artiq/compiler/module.py

+1 −0 artiq/compiler/transforms/__init__.py

+22 −0 artiq/compiler/transforms/cfg_simplifier.py

+3 −2 artiq/compiler/transforms/dead_code_eliminator.py

+4 −2 artiq/test/coredevice/portability.py
diff --git a/artiq/compiler/module.py b/artiq/compiler/module.py
@@ -55,6 +55,7 @@ def __init__(self, src, ref_period=1e-6):
         artiq_ir_generator = transforms.ARTIQIRGenerator(engine=self.engine,
                                                          module_name=src.name,
                                                          ref_period=ref_period)
+        cfg_simplifier = transforms.CFGSimplifier(engine=self.engine)
         dead_code_eliminator = transforms.DeadCodeEliminator(engine=self.engine)
         local_access_validator = validators.LocalAccessValidator(engine=self.engine)
         devirtualization = analyses.Devirtualization()
@@ -70,6 +71,7 @@ def __init__(self, src, ref_period=1e-6):
         devirtualization.visit(src.typedtree)
         self.artiq_ir = artiq_ir_generator.visit(src.typedtree)
         artiq_ir_generator.annotate_calls(devirtualization)
+        cfg_simplifier.process(self.artiq_ir)
         local_access_validator.process(self.artiq_ir)
         dead_code_eliminator.process(self.artiq_ir)
         interleaver.process(self.artiq_ir)

diff --git a/artiq/compiler/transforms/__init__.py b/artiq/compiler/transforms/__init__.py
@@ -4,5 +4,6 @@
 from .iodelay_estimator import IODelayEstimator
 from .artiq_ir_generator import ARTIQIRGenerator
 from .dead_code_eliminator import DeadCodeEliminator
+from .cfg_simplifier import CFGSimplifier
 from .llvm_ir_generator import LLVMIRGenerator
 from .interleaver import Interleaver
diff --git a/artiq/compiler/transforms/cfg_simplifier.py b/artiq/compiler/transforms/cfg_simplifier.py
@@ -0,0 +1,22 @@
+"""
+:class:`CFGSimplifier` is a simple control flow graph
+simplification transform: it removes empty basic blocks.
+"""
+
+from .. import ir
+
+class CFGSimplifier:
+    def __init__(self, engine):
+        self.engine = engine
+
+    def process(self, functions):
+        for func in functions:
+            self.process_function(func)
+
+    def process_function(self, func):
+        for block in list(func.basic_blocks):
+            if len(block.instructions) == 1 and \
+                    isinstance(block.terminator(), ir.Branch):
+                successor, = block.successors()
+                block.replace_all_uses_with(successor)
+                block.erase()
diff --git a/artiq/compiler/transforms/dead_code_eliminator.py b/artiq/compiler/transforms/dead_code_eliminator.py
@@ -1,6 +1,7 @@
 """
-:class:`DeadCodeEliminator` is a very simple dead code elimination
-transform: it only removes basic blocks with no predecessors.
+:class:`DeadCodeEliminator` is a dead code elimination transform:
+it only basic blocks with no predecessors as well as unused
+instructions without side effects.
 """
 
 from .. import ir

diff --git a/artiq/test/coredevice/portability.py b/artiq/test/coredevice/portability.py
@@ -42,10 +42,13 @@ def build(self):
         self.al = [1, 2, 3, 4, 5]
         self.list_copy_in = [2*Hz, 10*MHz]
 
+        self.half_input = 0
+        self.acc = 0
+        self.list_copy_out = []
+
     @kernel
     def run(self):
         self.half_input = self.input//2
-        self.decimal_fraction = Fraction("1.2")
         self.acc = 0
         for i in range(len(self.al)):
             self.acc += self.al[i]
@@ -190,7 +193,6 @@ def test_misc(self):
         for f in self.execute, _run_on_host:
             uut = f(_Misc)
             self.assertEqual(uut.half_input, 42)
-            self.assertEqual(uut.decimal_fraction, Fraction("1.2"))
             self.assertEqual(uut.acc, sum(uut.al))
             self.assertEqual(uut.list_copy_in, uut.list_copy_out)