SPV OpAtomicCompareSwap: Generate correct operand order and number of operands.

SPIRV/GlslangToSpv.cpp

@@ -2526,14 +2526,21 @@ spv::Id TGlslangToSpvTraverser::createAtomicOperation(glslang::TOperator op, spv
     // Sort out the operands
     //  - mapping from glslang -> SPV
     //  - there are extra SPV operands with no glslang source
+    //  - compare-exchange swaps the value and comparator
+    //  - compare-exchange has an extra memory semantics
     std::vector<spv::Id> spvAtomicOperands;  // hold the spv operands
     auto opIt = operands.begin();            // walk the glslang operands
     spvAtomicOperands.push_back(*(opIt++));
     spvAtomicOperands.push_back(builder.makeUintConstant(spv::ScopeDevice));     // TBD: what is the correct scope?
     spvAtomicOperands.push_back(builder.makeUintConstant(spv::MemorySemanticsMaskNone)); // TBD: what are the correct memory semantics?
+    if (opCode == spv::OpAtomicCompareExchange) {
+        spvAtomicOperands.push_back(builder.makeUintConstant(spv::MemorySemanticsMaskNone)); // TBD: what are the correct memory semantics?
+        spvAtomicOperands.push_back(*(opIt + 1));
+        spvAtomicOperands.push_back(*opIt);
+        opIt += 2;
+    }
 
-    // Add the rest of the operands, skipping the first one, which was dealt with above.
-    // For some ops, there are none, for some 1, for compare-exchange, 2.
+    // Add the rest of the operands, skipping any that were dealt with above.
     for (; opIt != operands.end(); ++opIt)
         spvAtomicOperands.push_back(*opIt);
 

Test/baseResults/spv.atomic.comp.out

@@ -120,7 +120,7 @@ TBD functionality: Is atomic_uint an opaque handle in the uniform storage class,
                               Store 38(origi) 64
               65:      6(int) Load 46(atomu)
               67:      6(int) Load 48(value)
-              68:      6(int) AtomicCompareExchange 65 15 16 66 67
+              68:      6(int) AtomicCompareExchange 65 15 16 16 67 66
                               Store 44(origu) 68
                               Return
                               FunctionEnd

glslang/Include/revision.h

@@ -2,5 +2,5 @@
 // For the version, it uses the latest git tag followed by the number of commits.
 // For the date, it uses the current date (when then script is run).
 
-#define GLSLANG_REVISION "3.0.753"
+#define GLSLANG_REVISION "3.0.754"
 #define GLSLANG_DATE "14-Sep-2015"