Merge remote-tracking branch 'origin/master' into xc7mux

3 files changed, 23 insertions, 7 deletions

diff --git a/passes/pmgen/README.md b/passes/pmgen/README.md
index 7a46558b1..d0711c730 100644
--- a/passes/pmgen/README.md
+++ b/passes/pmgen/README.md
@@ -29,19 +29,25 @@ up in any future matches:
 
     pm.blacklist(some_cell);
 
-The `.run(callback_function)` method searches for all matches and calls the
-callback function for each found match:
+The `.run_<pattern_name>(callback_function)` method searches for all matches
+for the pattern`<pattern_name>` and calls the callback function for each found
+match:
 
-    pm.run([&](){
+    pm.run_foobar([&](){
         log("found matching 'foo' cell: %s\n", log_id(pm.st.foo));
         log("          with 'bar' cell: %s\n", log_id(pm.st.bar));
     });
 
 The `.pmg` file declares matcher state variables that are accessible via the
-`.st.<state_name>` members. (The `.st` member is of type `foobar_pm::state_t`.)
+`.st_<pattern_name>.<state_name>` members. (The `.st_<pattern_name>` member is
+of type `foobar_pm::state_<pattern_name>_t`.)
 
 Similarly the `.pmg` file declares user data variables that become members of
-`.ud`, a struct of type `foobar_pm::udata_t`.
+`.ud_<pattern_name>`, a struct of type `foobar_pm::udata_<pattern_name>_t`.
+
+There are four versions of the `run_<pattern_name>()` method: Without callback,
+callback without arguments, callback with reference to `pm`, and callback with
+reference to `pm.st_<pattern_name>`.
 
 
 The .pmg File Format
@@ -52,6 +58,12 @@ lines consist of whitespace-separated tokens.
 
 Lines in `.pmg` files starting with `//` are comments.
 
+Declaring a pattern
+-------------------
+
+A `.pmg` file contains one or more patterns. Each pattern starts with a line
+with the `pattern` keyword followed by the name of the pattern.
+
 Declaring state variables
 -------------------------
 
@@ -66,7 +78,7 @@ State variables are automatically managed by the generated backtracking algorith
 and saved and restored as needed.
 
 They are automatically initialized to the default constructed value of their type
-when `.run(callback_function)` is called.
+when `.run_<pattern_name>(callback_function)` is called.
 
 Declaring udata variables
 -------------------------
diff --git a/passes/pmgen/peepopt.cc b/passes/pmgen/peepopt.cc
index 78eb68c7a..e7f95cf85 100644
--- a/passes/pmgen/peepopt.cc
+++ b/passes/pmgen/peepopt.cc
@@ -40,7 +40,7 @@ struct PeepoptPass : public Pass {
 	}
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 	{
-		log_header(design, "Executing PEEOPOPT pass (run peephole optimizers).\n");
+		log_header(design, "Executing PEEPOPT pass (run peephole optimizers).\n");
 
 		size_t argidx;
 		for (argidx = 1; argidx < args.size(); argidx++)
diff --git a/passes/pmgen/peepopt_shiftmul.pmg b/passes/pmgen/peepopt_shiftmul.pmg
index 1f9b3c2b9..fe861b728 100644
--- a/passes/pmgen/peepopt_shiftmul.pmg
+++ b/passes/pmgen/peepopt_shiftmul.pmg
@@ -8,9 +8,13 @@ endmatch
 
 code shamt
 	shamt = port(shift, \B);
+	if (shamt.empty())
+		reject;
 	if (shamt[GetSize(shamt)-1] == State::S0) {
 		do {
 			shamt.remove(GetSize(shamt)-1);
+			if (shamt.empty())
+				reject;
 		} while (shamt[GetSize(shamt)-1] == State::S0);
 	} else
 	if (shift->type.in($shift, $shiftx) && param(shift, \B_SIGNED).as_bool()) {