Improved SCCP, inlining and resource specialization passes, legalize `ImageSubscript` for GLSL (#2146)

1 files changed, 36 insertions, 0 deletions

diff --git a/source/slang/slang-ir-ssa-simplification.cpp b/source/slang/slang-ir-ssa-simplification.cpp
new file mode 100644
index 000000000..fcc6dc4ae
--- /dev/null
+++ b/source/slang/slang-ir-ssa-simplification.cpp
@@ -0,0 +1,36 @@
+// slang-ir-ssa-simplification.cpp
+#include "slang-ir-ssa-simplification.h"
+#include "slang-ir.h"
+#include "slang-ir-ssa.h"
+#include "slang-ir-sccp.h"
+#include "slang-ir-dce.h"
+#include "slang-ir-simplify-cfg.h"
+
+namespace Slang
+{
+    struct IRModule;
+
+    // Run a combination of SSA, SCCP, SimplifyCFG, and DeadCodeElimination pass
+    // until no more changes are possible.
+    void simplifyIR(IRModule* module)
+    {
+        bool changed = true;
+        const int kMaxIterations = 8;
+        int iterationCounter = 0;
+        while (changed && iterationCounter < kMaxIterations)
+        {
+            changed = false;
+            changed |= applySparseConditionalConstantPropagation(module);
+            changed |= simplifyCFG(module);
+
+            // Note: we disregard the `changed` state from dead code elimination pass since
+            // SCCP pass could be generating temporarily evaluated constant values and never actually use them.
+            // DCE will always remove those nearly generated consts and always returns true here.
+            eliminateDeadCode(module);
+
+            changed |= constructSSA(module);
+
+            iterationCounter++;
+        }
+    }
+}