From d74cc6397b4d019662f5e42b88776a4d381c32e3 Mon Sep 17 00:00:00 2001
From: Matt Pharr <matt.pharr@intel.com>
Date: Mon, 19 Mar 2012 15:06:35 -0700
Subject: [PATCH] Fix significant bug in mask management in code generated for
 'foreach'.

In particular, we 1. weren't setting the function mask to 'all on', such that
any mixed function mask would in turn apply inside the foreach loop, and 2.
weren't always setting the internal mask to 'all on' before doing any additional
masking based on the iteration variables.
---
 stmt.cpp                  |  6 ++++++
 tests/foreach-mask-1.ispc | 21 +++++++++++++++++++++
 tests/foreach-mask.ispc   | 25 +++++++++++++++++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 tests/foreach-mask-1.ispc
 create mode 100644 tests/foreach-mask.ispc

diff --git a/stmt.cpp b/stmt.cpp
index c8293b5c..a9905096 100644
--- a/stmt.cpp
+++ b/stmt.cpp
@@ -1336,10 +1336,14 @@ ForeachStmt::EmitCode(FunctionEmitContext *ctx) const {
     llvm::BasicBlock *bbExit = ctx->CreateBasicBlock("foreach_exit");
 
     llvm::Value *oldMask = ctx->GetInternalMask();
+    llvm::Value *oldFunctionMask = ctx->GetFunctionMask();
 
     ctx->SetDebugPos(pos);
     ctx->StartScope();
 
+    ctx->SetInternalMask(LLVMMaskAllOn);
+    ctx->SetFunctionMask(LLVMMaskAllOn);
+
     // This should be caught during typechecking
     Assert(startExprs.size() == dimVariables.size() && 
            endExprs.size() == dimVariables.size());
@@ -1765,7 +1769,9 @@ ForeachStmt::EmitCode(FunctionEmitContext *ctx) const {
     ///////////////////////////////////////////////////////////////////////////
     // foreach_exit: All done.  Restore the old mask and clean up
     ctx->SetCurrentBasicBlock(bbExit);
+
     ctx->SetInternalMask(oldMask);
+    ctx->SetFunctionMask(oldFunctionMask);
 
     ctx->EndForeach();
     ctx->EndScope();
diff --git a/tests/foreach-mask-1.ispc b/tests/foreach-mask-1.ispc
new file mode 100644
index 00000000..2f462b48
--- /dev/null
+++ b/tests/foreach-mask-1.ispc
@@ -0,0 +1,21 @@
+
+export uniform int width() { return programCount; }
+
+
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform float val[programCount+3];
+    for (uniform int i = 0; i < programCount+3; ++i)
+        val[i] = 0;
+
+    // make sure we reset the func mask in the foreach loop...
+    if ((int)aFOO[programIndex] & 1)
+        foreach (i = 0 ... programCount+3)
+            val[i] += aFOO[i] - 1;
+
+    RET[programIndex] = val[3+programIndex]; 
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = programIndex+3;
+}
diff --git a/tests/foreach-mask.ispc b/tests/foreach-mask.ispc
new file mode 100644
index 00000000..0d01b16a
--- /dev/null
+++ b/tests/foreach-mask.ispc
@@ -0,0 +1,25 @@
+
+export uniform int width() { return programCount; }
+
+
+// make sure we reset the func mask in the foreach loop...
+
+void update(uniform float val[], const uniform float a[]) {
+    foreach (i = 0 ... programCount+3)
+        val[i] += a[i] - 1;
+}
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform float val[programCount+3];
+    for (uniform int i = 0; i < programCount+3; ++i)
+        val[i] = 0;
+
+    if ((int)aFOO[programIndex] & 1)
+        update(val, aFOO);
+
+    RET[programIndex] = val[3+programIndex]; 
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = programIndex+3;
+}