Lower int/uint/bool matrices to arrays for SPIRV (#7687)

* Add tests for expected behaviour

* Allow matrix types in logical or/and

* Legalize int/bool matrix types and construction with makeMatrix

* Legalize uint matrices and operations

* Limit testing to only SPIRV

* Better tests for int and bool

* Add test for uint

* Remove GLSL tests

* Remove old test for diagnosing int matrices

* Emit SPIRV directly in tests

* format code

* Address PR comments

* Improve testing

* Address PR comments

* format code

* Add tests for matrix intrinsic operations

* Move matrix lowering to dedicated legalization pass

* Fix compiler warning

* Remove signal again

* Reorder matrix and vector legalization

* Fix formatting

* Add shift and comparison tests

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

9 files changed, 435 insertions, 130 deletions

diff --git a/source/slang/hlsl.meta.slang b/source/slang/hlsl.meta.slang
index 264098bec..2ac886f61 100644
--- a/source/slang/hlsl.meta.slang
+++ b/source/slang/hlsl.meta.slang
@@ -8616,6 +8616,55 @@ T determinant(matrix<T,N,N> m)
     }
 }
 
+/// @param m The matrix.
+/// @return The determinant of the matrix.
+/// @category math
+__generic<T : __BuiltinIntegerType, let N : int>
+[__readNone]
+[require(glsl_hlsl_metal_spirv_wgsl)]
+T determinant(matrix<T,N,N> m)
+{
+    __target_switch
+    {
+    case glsl: __intrinsic_asm "determinant";
+    case hlsl: __intrinsic_asm "determinant";
+    case metal: __intrinsic_asm "determinant";
+    case wgsl: __intrinsic_asm "determinant";
+    // SPIR-V doesn't support integer determinants, so we need to implement it manually
+    default:
+        static_assert(N >= 1 && N <= 4, "determinant is only implemented up to 4x4 matrices");
+        if (N == 1)
+        {
+            return m[0][0];
+        }
+        else if (N == 2)
+        {
+            return m[0][0] * m[1][1] - m[0][1] * m[1][0];
+        }
+        else if (N == 3)
+        {
+            return
+                m[0][0] * (m[1][1] * m[2][2] - m[1][2] * m[2][1])
+              - m[0][1] * (m[1][0] * m[2][2] - m[1][2] * m[2][0])
+              + m[0][2] * (m[1][0] * m[2][1] - m[1][1] * m[2][0]);
+        }
+        else// if (N == 4)
+        {
+            T a = m[2][2] * m[3][3] - m[2][3] * m[3][2];
+            T b = m[2][1] * m[3][3] - m[2][3] * m[3][1];
+            T c = m[2][1] * m[3][2] - m[2][2] * m[3][1];
+            T d = m[2][0] * m[3][3] - m[2][3] * m[3][0];
+            T e = m[2][0] * m[3][2] - m[2][2] * m[3][0];
+            T f = m[2][0] * m[3][1] - m[2][1] * m[3][0];
+            return
+                m[0][0] * (m[1][1] * a - m[1][2] * b + m[1][3] * c)
+              - m[0][1] * (m[1][0] * a - m[1][2] * d + m[1][3] * e)
+              + m[0][2] * (m[1][0] * b - m[1][1] * d + m[1][3] * f)
+              - m[0][3] * (m[1][0] * c - m[1][1] * e + m[1][2] * f);
+        }
+    }
+}
+
 /// Barrier for device memory.
 /// @category barrier
 __glsl_extension(GL_KHR_memory_scope_semantics)
@@ -13720,10 +13769,8 @@ matrix<T, M, N> transpose(matrix<T, N, M> x)
     {
     case glsl: __intrinsic_asm "transpose";
     case hlsl: __intrinsic_asm "transpose";
-    case spirv: return spirv_asm {
-        OpTranspose $$matrix<T, M, N> result $x
-    };
     case wgsl: __intrinsic_asm "transpose";
+    // SPIRV-V doenst't support integer matrices, so transpose it manually
     default:
         matrix<T, M, N> result;
         for (int r = 0; r < M; ++r)
diff --git a/source/slang/slang-diagnostic-defs.h b/source/slang/slang-diagnostic-defs.h
index 0ce5d9f47..3dafda3be 100644
--- a/source/slang/slang-diagnostic-defs.h
+++ b/source/slang/slang-diagnostic-defs.h
@@ -2201,12 +2201,6 @@ DIAGNOSTIC(
 DIAGNOSTIC(39999, Fatal, complationCeased, "compilation ceased")
 
 DIAGNOSTIC(
-    38202,
-    Error,
-    matrixWithDisallowedElementTypeEncountered,
-    "matrix with disallowed element type '$0' encountered")
-
-DIAGNOSTIC(
     38203,
     Error,
     vectorWithDisallowedElementTypeEncountered,
diff --git a/source/slang/slang-emit-spirv.cpp b/source/slang/slang-emit-spirv.cpp
index 2b6f1c821..bbed44c51 100644
--- a/source/slang/slang-emit-spirv.cpp
+++ b/source/slang/slang-emit-spirv.cpp
@@ -216,7 +216,7 @@ struct SpvInst : SpvInstParent
         //
         // > Word Count: The complete number of words taken by an instruction,
         // > including the word holding the word count and opcode, and any optional
-        // > operands. An instruction’s word count is the total space taken by the instruction.
+        // > operands. An instruction's word count is the total space taken by the instruction.
         //
         SpvWord wordCount = 1 + SpvWord(operandWordsCount);
 
@@ -360,7 +360,7 @@ struct SpvLiteralBits
         // > UTF-8 encoding scheme. The UTF-8 octets (8-bit bytes) are packed
         // > four per word, following the little-endian convention (i.e., the
         // > first octet is in the lowest-order 8 bits of the word).
-        // > The final word contains the string’s nul-termination character (0), and
+        // > The final word contains the string's nul-termination character (0), and
         // > all contents past the end of the string in the final word are padded with 0.
 
         // First work out the amount of words we'll need
@@ -2039,17 +2039,24 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         case kIROp_MatrixType:
             {
                 auto matrixType = static_cast<IRMatrixType*>(inst);
+                auto elementType = matrixType->getElementType();
+
+                // SPIR-V only supports floating-point matrices
+                // bool/int matrices should be lowered to
+                // arrays of vectors before reaching here
+                SLANG_ASSERT(!as<IRBoolType>(elementType));
+                SLANG_ASSERT(!as<IRIntType>(elementType));
+                SLANG_ASSERT(!as<IRUIntType>(elementType));
+
                 auto vectorSpvType = ensureVectorType(
-                    static_cast<IRBasicType*>(matrixType->getElementType())->getBaseType(),
+                    static_cast<IRBasicType*>(elementType)->getBaseType(),
                     static_cast<IRIntLit*>(matrixType->getColumnCount())->getValue(),
                     nullptr);
                 const auto columnCount =
                     static_cast<IRIntLit*>(matrixType->getRowCount())->getValue();
-                auto matrixSPVType = emitOpTypeMatrix(
-                    inst,
-                    vectorSpvType,
-                    SpvLiteralInteger::from32(int32_t(columnCount)));
-                return matrixSPVType;
+                const auto columnCountSpv = SpvLiteralInteger::from32(int32_t(columnCount));
+                SpvInst* matrixSpvType = emitOpTypeMatrix(inst, vectorSpvType, columnCountSpv);
+                return matrixSpvType;
             }
         case kIROp_ArrayType:
         case kIROp_UnsizedArrayType:
@@ -2621,7 +2628,7 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         SpvWord arrayed =
             inst->isArray() ? ImageOpConstants::isArrayed : ImageOpConstants::notArrayed;
 
-        // Vulkan spec 16.1: "The “Depth” operand of OpTypeImage is ignored."
+        // Vulkan spec 16.1: "The "Depth" operand of OpTypeImage is ignored."
         SpvWord depth =
             ImageOpConstants::unknownDepthImage; // No knowledge of if this is a depth image
         SpvWord ms = inst->isMultisample() ? ImageOpConstants::isMultisampled
@@ -7767,12 +7774,40 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         // Otherwise, operands are raw elements, we need to construct row vectors first,
         // then construct matrix from row vectors.
         List<SpvInst*> rowVectors;
-        auto matrixType = as<IRMatrixType>(inst->getDataType());
-        auto rowCount = getIntVal(matrixType->getRowCount());
-        auto colCount = getIntVal(matrixType->getColumnCount());
+
+        IRIntegerValue rowCount;
+        IRIntegerValue colCount;
+        IRType* elementType;
+
+        // Data type can be either matrix or vector depending on the
+        // legalization requirements
+        auto dataType = inst->getDataType();
+
+        if (auto matrixType = as<IRMatrixType>(dataType))
+        {
+            elementType = matrixType->getElementType();
+            rowCount = getIntVal(matrixType->getRowCount());
+            colCount = getIntVal(matrixType->getColumnCount());
+        }
+        else if (auto arrayType = as<IRArrayType>(dataType))
+        {
+            auto vectorType = as<IRVectorType>(arrayType->getElementType());
+            SLANG_ASSERT(vectorType);
+
+            elementType = vectorType->getElementType();
+            rowCount = getIntVal(arrayType->getElementCount());
+            colCount = getIntVal(vectorType->getElementCount());
+        }
+        else
+        {
+            SLANG_UNEXPECTED("data type for makeMatrix operation is "
+                             "expected be either a matrix or array type");
+        }
+
         IRBuilder builder(inst);
         builder.setInsertBefore(inst);
-        auto rowVectorType = builder.getVectorType(matrixType->getElementType(), colCount);
+        auto rowVectorType = builder.getVectorType(elementType, colCount);
+
         List<IRInst*> colElements;
         UInt index = 0;
         for (IRIntegerValue j = 0; j < rowCount; j++)
@@ -7897,7 +7932,10 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         ArrayView<IRInst*> operands)
     {
         IRType* elementType = getVectorOrCoopMatrixElementType(operands[0]->getDataType());
+        SLANG_ASSERT(elementType);
+
         IRBasicType* basicType = as<IRBasicType>(elementType);
+        SLANG_ASSERT(basicType);
 
         SpvOp opCode = _arithmeticOpCodeConvert(op, basicType);
         if (opCode == SpvOpUndef)
@@ -7958,6 +7996,52 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         SLANG_UNREACHABLE("Arithmetic op with 0 or more than 2 operands");
     }
 
+    // Helper method to handle composite arithmetic operations for matrices and arrays
+    SpvInst* emitCompositeArithmetic(
+        SpvInstParent* parent,
+        IRInst* inst,
+        IRIntegerValue rowCount,
+        IRIntegerValue colCount,
+        IRType* elementType,
+        IRType* resultType,
+        bool isMatrixType)
+    {
+        IRBuilder builder(inst);
+        builder.setInsertBefore(inst);
+        auto rowVectorType = builder.getVectorType(elementType, colCount);
+        List<SpvInst*> rows;
+
+        for (IRIntegerValue i = 0; i < rowCount; i++)
+        {
+            List<IRInst*> operands;
+            for (UInt j = 0; j < inst->getOperandCount(); j++)
+            {
+                auto originalOperand = inst->getOperand(j);
+                bool shouldExtract =
+                    isMatrixType ? as<IRMatrixType>(originalOperand->getDataType()) != nullptr
+                                 : as<IRArrayType>(originalOperand->getDataType()) != nullptr;
+
+                if (shouldExtract)
+                {
+                    auto operand = builder.emitElementExtract(originalOperand, i);
+                    emitLocalInst(parent, operand);
+                    operands.add(operand);
+                }
+                else
+                {
+                    operands.add(originalOperand);
+                }
+            }
+            rows.add(emitVectorOrScalarArithmetic(
+                parent,
+                nullptr,
+                rowVectorType,
+                inst->getOp(),
+                inst->getOperandCount(),
+                operands.getArrayView()));
+        }
+        return emitCompositeConstruct(parent, inst, resultType, rows);
+    }
 
     SpvInst* emitArithmetic(SpvInstParent* parent, IRInst* inst)
     {
@@ -7965,36 +8049,38 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         {
             auto rowCount = getIntVal(matrixType->getRowCount());
             auto colCount = getIntVal(matrixType->getColumnCount());
-            IRBuilder builder(inst);
-            builder.setInsertBefore(inst);
-            auto rowVectorType = builder.getVectorType(matrixType->getElementType(), colCount);
-            List<SpvInst*> rows;
-            for (IRIntegerValue i = 0; i < rowCount; i++)
-            {
-                List<IRInst*> operands;
-                for (UInt j = 0; j < inst->getOperandCount(); j++)
-                {
-                    auto originalOperand = inst->getOperand(j);
-                    if (as<IRMatrixType>(originalOperand->getDataType()))
-                    {
-                        auto operand = builder.emitElementExtract(originalOperand, i);
-                        emitLocalInst(parent, operand);
-                        operands.add(operand);
-                    }
-                    else
-                    {
-                        operands.add(originalOperand);
-                    }
-                }
-                rows.add(emitVectorOrScalarArithmetic(
-                    parent,
-                    nullptr,
-                    rowVectorType,
-                    inst->getOp(),
-                    inst->getOperandCount(),
-                    operands.getArrayView()));
-            }
-            return emitCompositeConstruct(parent, inst, inst->getDataType(), rows);
+            return emitCompositeArithmetic(
+                parent,
+                inst,
+                rowCount,
+                colCount,
+                matrixType->getElementType(),
+                inst->getDataType(),
+                true);
+        }
+        else if (const auto arrayType = as<IRArrayType>(inst->getDataType()))
+        {
+            // Only for legalization
+            auto arrayElementType = arrayType->getElementType();
+            SLANG_ASSERT(as<IRVectorType>(arrayElementType));
+
+            auto vectorType = as<IRVectorType>(arrayElementType);
+            auto elementType = vectorType->getElementType();
+            SLANG_ASSERT(
+                as<IRBoolType>(elementType) || as<IRUIntType>(elementType) ||
+                as<IRIntType>(elementType));
+
+            auto rowCount = getIntVal(arrayType->getElementCount());
+            auto colCount = getIntVal(vectorType->getElementCount());
+
+            return emitCompositeArithmetic(
+                parent,
+                inst,
+                rowCount,
+                colCount,
+                elementType,
+                inst->getDataType(),
+                false);
         }
 
         Array<IRInst*, 4> operands;
diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index f40679bd9..067b5a551 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -61,6 +61,7 @@
 #include "slang-ir-legalize-empty-array.h"
 #include "slang-ir-legalize-global-values.h"
 #include "slang-ir-legalize-image-subscript.h"
+#include "slang-ir-legalize-matrix-types.h"
 #include "slang-ir-legalize-mesh-outputs.h"
 #include "slang-ir-legalize-uniform-buffer-load.h"
 #include "slang-ir-legalize-varying-params.h"
@@ -1334,6 +1335,7 @@ Result linkAndOptimizeIR(
         legalizeEmptyTypes(targetProgram, irModule, sink);
     }
 
+    legalizeMatrixTypes(targetProgram, irModule, sink);
     legalizeVectorTypes(irModule, sink);
 
     // Once specialization and type legalization have been performed,
diff --git a/source/slang/slang-ir-legalize-binary-operator.cpp b/source/slang/slang-ir-legalize-binary-operator.cpp
index f2f7cdef2..24ba61fc6 100644
--- a/source/slang/slang-ir-legalize-binary-operator.cpp
+++ b/source/slang/slang-ir-legalize-binary-operator.cpp
@@ -176,93 +176,124 @@ void legalizeBinaryOp(IRInst* inst, DiagnosticSink* sink, CodeGenTarget target)
 
 void legalizeLogicalAndOr(IRInst* inst)
 {
-    switch (inst->getOp())
+    auto op = inst->getOp();
+    if (op == kIROp_And || op == kIROp_Or)
     {
-    case kIROp_And:
-    case kIROp_Or:
+        IRBuilder builder(inst);
+        builder.setInsertBefore(inst);
+
+        // Logical-AND and logical-OR takes boolean types as its operands.
+        // If they are not, legalize them by casting to boolean type.
+        //
+        SLANG_ASSERT(inst->getOperandCount() == 2);
+        for (UInt i = 0; i < 2; i++)
         {
-            IRBuilder builder(inst);
-            builder.setInsertBefore(inst);
-
-            // Logical-AND and logical-OR takes boolean types as its operands.
-            // If they are not, legalize them by casting to boolean type.
-            //
-            SLANG_ASSERT(inst->getOperandCount() == 2);
-            for (UInt i = 0; i < 2; i++)
-            {
-                auto operand = inst->getOperand(i);
-                auto operandDataType = operand->getDataType();
+            auto operand = inst->getOperand(i);
+            auto operandDataType = operand->getDataType();
 
-                if (auto vecType = as<IRVectorType>(operandDataType))
-                {
-                    if (!as<IRBoolType>(vecType->getElementType()))
-                    {
-                        // Cast operand to vector<bool,N>
-                        auto elemCount = vecType->getElementCount();
-                        auto vb = builder.getVectorType(builder.getBoolType(), elemCount);
-                        auto v = builder.emitCast(vb, operand);
-                        builder.replaceOperand(inst->getOperands() + i, v);
-                    }
-                }
-                else if (!as<IRBoolType>(operandDataType))
-                {
-                    // Cast operand to bool
-                    auto s = builder.emitCast(builder.getBoolType(), operand);
-                    builder.replaceOperand(inst->getOperands() + i, s);
-                }
-            }
+            SLANG_ASSERT(
+                as<IRMatrixType>(operandDataType) || as<IRVectorType>(operandDataType) ||
+                as<IRArrayType>(operandDataType) || as<IRBoolType>(operandDataType));
 
-            // Legalize the return type; mostly for SPIRV.
-            // The return type of OpLogicalOr must be boolean type.
-            // If not, we need to recreate the instruction with boolean return type.
-            // Then, we have to cast it back to the original type so that other instrucitons that
-            // use have the matching types.
-            //
-            auto dataType = inst->getDataType();
-            auto lhs = inst->getOperand(0);
-            auto rhs = inst->getOperand(1);
-            IRInst* newInst = nullptr;
-
-            if (auto vecType = as<IRVectorType>(dataType))
+            if (auto vecType = as<IRVectorType>(operandDataType))
             {
                 if (!as<IRBoolType>(vecType->getElementType()))
                 {
-                    // Return type should be vector<bool,N>
+                    // Cast operand to vector<bool,N>
                     auto elemCount = vecType->getElementCount();
                     auto vb = builder.getVectorType(builder.getBoolType(), elemCount);
-
-                    if (inst->getOp() == kIROp_And)
-                    {
-                        newInst = builder.emitAnd(vb, lhs, rhs);
-                    }
-                    else
-                    {
-                        newInst = builder.emitOr(vb, lhs, rhs);
-                    }
-                    newInst = builder.emitCast(dataType, newInst);
+                    auto v = builder.emitCast(vb, operand);
+                    builder.replaceOperand(inst->getOperands() + i, v);
                 }
             }
-            else if (!as<IRBoolType>(dataType))
+        }
+
+        // Legalize the return type; mostly for SPIRV.
+        // The return type of OpLogicalOr must be boolean type.
+        // If not, we need to recreate the instruction with boolean return type.
+        // Then, we have to cast it back to the original type so that other instrucitons that
+        // use have the matching types.
+        //
+        auto dataType = inst->getDataType();
+        auto lhs = inst->getOperand(0);
+        auto rhs = inst->getOperand(1);
+        IRInst* newInst = nullptr;
+
+        SLANG_ASSERT(
+            as<IRMatrixType>(dataType) || as<IRVectorType>(dataType) || as<IRBoolType>(dataType) ||
+            as<IRArrayType>(dataType));
+        if (auto vecType = as<IRVectorType>(dataType))
+        {
+            if (!as<IRBoolType>(vecType->getElementType()))
             {
-                // Return type should be bool
+                // Return type should be vector<bool,N>
+                auto elemCount = vecType->getElementCount();
+                auto vb = builder.getVectorType(builder.getBoolType(), elemCount);
+
                 if (inst->getOp() == kIROp_And)
                 {
-                    newInst = builder.emitAnd(builder.getBoolType(), lhs, rhs);
+                    newInst = builder.emitAnd(vb, lhs, rhs);
                 }
                 else
                 {
-                    newInst = builder.emitOr(builder.getBoolType(), lhs, rhs);
+                    newInst = builder.emitOr(vb, lhs, rhs);
                 }
                 newInst = builder.emitCast(dataType, newInst);
             }
+        }
+        else if (auto arrayType = as<IRArrayType>(dataType))
+        {
+            // Handle lowered matrices (arrays of vectors)
+            auto arrayVecType = as<IRVectorType>(arrayType->getElementType());
+            SLANG_ASSERT(arrayVecType);
+
+            // At this point, lhs and rhs should already be converted to bool arrays
+            auto lhsArrayType = as<IRArrayType>(lhs->getDataType());
+            auto rhsArrayType = as<IRArrayType>(rhs->getDataType());
+            SLANG_ASSERT(lhsArrayType && rhsArrayType);
+
+            auto lhsVecType = as<IRVectorType>(lhsArrayType->getElementType());
+            auto rhsVecType = as<IRVectorType>(rhsArrayType->getElementType());
+            SLANG_ASSERT(lhsVecType && rhsVecType);
+
+            SLANG_ASSERT(
+                as<IRBoolType>(lhsVecType->getElementType()) &&
+                as<IRBoolType>(rhsVecType->getElementType()));
 
-            if (newInst && inst != newInst)
+            auto arraySize = arrayType->getElementCount();
+            List<IRInst*> resultElements;
+
+            // Extract each vector from both arrays, perform AND/OR, collect results
+            for (IRIntegerValue i = 0; i < getIntVal(arraySize); i++)
             {
-                inst->replaceUsesWith(newInst);
-                inst->removeAndDeallocate();
+                auto indexVal = builder.getIntValue(builder.getIntType(), i);
+                auto lhsElement = builder.emitElementExtract(lhs, indexVal);
+                auto rhsElement = builder.emitElementExtract(rhs, indexVal);
+
+                IRInst* resultElement;
+                if (inst->getOp() == kIROp_And)
+                {
+                    resultElement =
+                        builder.emitAnd(lhsElement->getDataType(), lhsElement, rhsElement);
+                }
+                else
+                {
+                    resultElement =
+                        builder.emitOr(lhsElement->getDataType(), lhsElement, rhsElement);
+                }
+                resultElements.add(resultElement);
             }
+
+            // Construct the result array from the individual vector results
+            newInst =
+                builder.emitMakeArray(dataType, getIntVal(arraySize), resultElements.getBuffer());
+        }
+
+        if (newInst && inst != newInst)
+        {
+            inst->replaceUsesWith(newInst);
+            inst->removeAndDeallocate();
         }
-        break;
     }
 
     for (auto child : inst->getModifiableChildren())
diff --git a/source/slang/slang-ir-legalize-matrix-types.cpp b/source/slang/slang-ir-legalize-matrix-types.cpp
new file mode 100644
index 000000000..0b972b5bd
--- /dev/null
+++ b/source/slang/slang-ir-legalize-matrix-types.cpp
@@ -0,0 +1,141 @@
+#include "slang-ir-legalize-matrix-types.h"
+
+#include "slang-compiler.h"
+#include "slang-ir-insts.h"
+#include "slang-ir-util.h"
+#include "slang-ir.h"
+
+namespace Slang
+{
+
+struct MatrixTypeLoweringContext
+{
+    TargetProgram* targetProgram;
+    IRModule* module;
+    DiagnosticSink* sink;
+
+    InstWorkList workList;
+    InstHashSet workListSet;
+
+    Dictionary<IRInst*, IRInst*> replacements;
+
+    MatrixTypeLoweringContext(TargetProgram* targetProgram, IRModule* module)
+        : targetProgram(targetProgram), module(module), workList(module), workListSet(module)
+    {
+    }
+
+    void addToWorkList(IRInst* inst)
+    {
+        for (auto ii = inst->getParent(); ii; ii = ii->getParent())
+        {
+            if (as<IRGeneric>(ii))
+                return;
+        }
+
+        if (workListSet.contains(inst))
+            return;
+
+        workList.add(inst);
+        workListSet.add(inst);
+    }
+
+    bool shouldLowerTarget()
+    {
+        auto target = targetProgram->getTargetReq()->getTarget();
+        switch (target)
+        {
+        case CodeGenTarget::SPIRV:
+        case CodeGenTarget::SPIRVAssembly:
+        case CodeGenTarget::GLSL:
+        case CodeGenTarget::WGSL:
+        case CodeGenTarget::WGSLSPIRV:
+        case CodeGenTarget::WGSLSPIRVAssembly:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+    bool shouldLowerMatrixType(IRMatrixType* matrixType)
+    {
+        if (!shouldLowerTarget())
+            return false;
+
+        auto elementType = matrixType->getElementType();
+        return as<IRBoolType>(elementType) || as<IRUIntType>(elementType) ||
+               as<IRIntType>(elementType);
+    }
+
+    IRInst* getReplacement(IRInst* inst)
+    {
+        if (auto replacement = replacements.tryGetValue(inst))
+            return *replacement;
+
+        IRInst* newInst = inst;
+
+        if (auto matrixType = as<IRMatrixType>(inst))
+        {
+            if (shouldLowerMatrixType(matrixType))
+            {
+                // Lower matrix<T, R, C> to T[R][C] (array of R vectors of length C)
+                auto elementType = matrixType->getElementType();
+                auto rowCount = matrixType->getRowCount();
+                auto columnCount = matrixType->getColumnCount();
+
+                IRBuilder builder(matrixType);
+                builder.setInsertBefore(matrixType);
+
+                // Create vector type for columns: vector<T, C>
+                auto vectorType = builder.getVectorType(elementType, columnCount);
+
+                // Create array type for rows: vector<T, C>[R]
+                auto arrayType = builder.getArrayType(vectorType, rowCount);
+
+                newInst = arrayType;
+            }
+        }
+
+        replacements[inst] = newInst;
+        return newInst;
+    }
+
+    void processModule()
+    {
+        addToWorkList(module->getModuleInst());
+
+        while (workList.getCount() != 0)
+        {
+            IRInst* inst = workList.getLast();
+
+            workList.removeLast();
+            workListSet.remove(inst);
+
+            // Run this inst through the replacer
+            getReplacement(inst);
+
+            for (auto child = inst->getLastChild(); child; child = child->getPrevInst())
+            {
+                addToWorkList(child);
+            }
+        }
+
+        // Apply all replacements
+        for (const auto& [old, replacement] : replacements)
+        {
+            if (old != replacement)
+            {
+                old->replaceUsesWith(replacement);
+                old->removeAndDeallocate();
+            }
+        }
+    }
+};
+
+void legalizeMatrixTypes(TargetProgram* targetProgram, IRModule* module, DiagnosticSink* sink)
+{
+    MatrixTypeLoweringContext context(targetProgram, module);
+    context.sink = sink;
+    context.processModule();
+}
+
+} // namespace Slang
\ No newline at end of file
diff --git a/source/slang/slang-ir-legalize-matrix-types.h b/source/slang/slang-ir-legalize-matrix-types.h
new file mode 100644
index 000000000..418e80a83
--- /dev/null
+++ b/source/slang/slang-ir-legalize-matrix-types.h
@@ -0,0 +1,13 @@
+#pragma once
+
+namespace Slang
+{
+
+struct IRModule;
+class DiagnosticSink;
+class TargetProgram;
+
+// Lower int/uint/bool matrix types to arrays for SPIRV, WGSL, and GLSL targets
+void legalizeMatrixTypes(TargetProgram* targetProgram, IRModule* module, DiagnosticSink* sink);
+
+} // namespace Slang
\ No newline at end of file
diff --git a/source/slang/slang-ir-util.cpp b/source/slang/slang-ir-util.cpp
index 1b11f8165..a1d043dff 100644
--- a/source/slang/slang-ir-util.cpp
+++ b/source/slang/slang-ir-util.cpp
@@ -453,6 +453,9 @@ void getTypeNameHint(StringBuilder& sb, IRInst* type)
 
     switch (type->getOp())
     {
+    case kIROp_BoolType:
+        sb << "bool";
+        break;
     case kIROp_FloatType:
         sb << "float";
         break;
diff --git a/source/slang/slang-ir-validate.cpp b/source/slang/slang-ir-validate.cpp
index bf5d8ed5d..156fe249f 100644
--- a/source/slang/slang-ir-validate.cpp
+++ b/source/slang/slang-ir-validate.cpp
@@ -598,21 +598,9 @@ void validateVectorsAndMatrices(
                 }
             }
 
-            // Verify that the element type is a floating point type, or an allowed integral type
-            auto elementType = matrixType->getElementType();
-            uint32_t allowedWidths = 0U;
-            if (isCPUTarget(targetRequest))
-                allowedWidths = 8U | 16U | 32U | 64U;
-            else if (isCUDATarget(targetRequest))
-                allowedWidths = 32U | 64U;
-            else if (isD3DTarget(targetRequest))
-                allowedWidths = 16U | 32U;
-            validateVectorOrMatrixElementType(
-                sink,
-                matrixType->sourceLoc,
-                elementType,
-                allowedWidths,
-                Diagnostics::matrixWithDisallowedElementTypeEncountered);
+            // Matrix element type validation removed to allow integer/bool matrices
+            // which will be lowered to arrays of vectors on targets that don't support them
+            // natively
         }
         else if (auto vectorType = as<IRVectorType>(globalInst))
         {