diff --git a/source/opt/folding_rules.cpp b/source/opt/folding_rules.cpp
index c879a0c..d15ad04 100644
--- a/source/opt/folding_rules.cpp
+++ b/source/opt/folding_rules.cpp
@@ -1430,6 +1430,64 @@
   };
 }
 
+// Replaces |inst| inplace with an FMA instruction |(x*y)+a|.
+void ReplaceWithFma(Instruction* inst, uint32_t x, uint32_t y, uint32_t a) {
+  uint32_t ext =
+      inst->context()->get_feature_mgr()->GetExtInstImportId_GLSLstd450();
+
+  if (ext == 0) {
+    inst->context()->AddExtInstImport("GLSL.std.450");
+    ext = inst->context()->get_feature_mgr()->GetExtInstImportId_GLSLstd450();
+    assert(ext != 0 &&
+           "Could not add the GLSL.std.450 extended instruction set");
+  }
+
+  std::vector<Operand> operands;
+  operands.push_back({SPV_OPERAND_TYPE_ID, {ext}});
+  operands.push_back({SPV_OPERAND_TYPE_LITERAL_INTEGER, {GLSLstd450Fma}});
+  operands.push_back({SPV_OPERAND_TYPE_ID, {x}});
+  operands.push_back({SPV_OPERAND_TYPE_ID, {y}});
+  operands.push_back({SPV_OPERAND_TYPE_ID, {a}});
+
+  inst->SetOpcode(SpvOpExtInst);
+  inst->SetInOperands(std::move(operands));
+}
+
+// Folds a multiple and add into an Fma.
+//
+// Cases:
+// (x * y) + a = Fma x y a
+// a + (x * y) = Fma x y a
+bool MergeMulAddArithmetic(IRContext* context, Instruction* inst,
+                           const std::vector<const analysis::Constant*>&) {
+  assert(inst->opcode() == SpvOpFAdd);
+
+  if (!inst->IsFloatingPointFoldingAllowed()) {
+    return false;
+  }
+
+  analysis::DefUseManager* def_use_mgr = context->get_def_use_mgr();
+  for (int i = 0; i < 2; i++) {
+    uint32_t op_id = inst->GetSingleWordInOperand(i);
+    Instruction* op_inst = def_use_mgr->GetDef(op_id);
+
+    if (op_inst->opcode() != SpvOpFMul) {
+      continue;
+    }
+
+    if (!op_inst->IsFloatingPointFoldingAllowed()) {
+      continue;
+    }
+
+    uint32_t x = op_inst->GetSingleWordInOperand(0);
+    uint32_t y = op_inst->GetSingleWordInOperand(1);
+    uint32_t a = inst->GetSingleWordInOperand((i + 1) % 2);
+    ReplaceWithFma(inst, x, y, a);
+    return true;
+  }
+  return false;
+}
+
 FoldingRule IntMultipleBy1() {
   return [](IRContext*, Instruction* inst,
             const std::vector<const analysis::Constant*>& constants) {
@@ -2543,6 +2601,7 @@
   rules_[SpvOpFAdd].push_back(MergeAddSubArithmetic());
   rules_[SpvOpFAdd].push_back(MergeGenericAddSubArithmetic());
   rules_[SpvOpFAdd].push_back(FactorAddMuls());
+  rules_[SpvOpFAdd].push_back(MergeMulAddArithmetic);
 
   rules_[SpvOpFDiv].push_back(RedundantFDiv());
   rules_[SpvOpFDiv].push_back(ReciprocalFDiv());
diff --git a/test/opt/fold_test.cpp b/test/opt/fold_test.cpp
index 7565ca7..2ca3256 100644
--- a/test/opt/fold_test.cpp
+++ b/test/opt/fold_test.cpp
@@ -7108,6 +7108,214 @@
         3, true)
  ));
 
+INSTANTIATE_TEST_SUITE_P(FmaGenerationMatchingTest, MatchingInstructionFoldingTest,
+::testing::Values(
+   // Test case 0: (x * y) + a = Fma(x, y, a)
+   InstructionFoldingCase<bool>(
+       Header() +
+           "; CHECK: [[ext:%\\w+]] = OpExtInstImport \"GLSL.std.450\"\n" +
+           "; CHECK: OpFunction\n" +
+           "; CHECK: [[x:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[y:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[a:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[lx:%\\w+]] = OpLoad {{%\\w+}} [[x]]\n" +
+           "; CHECK: [[ly:%\\w+]] = OpLoad {{%\\w+}} [[y]]\n" +
+           "; CHECK: [[la:%\\w+]] = OpLoad {{%\\w+}} [[a]]\n" +
+           "; CHECK: [[fma:%\\w+]] = OpExtInst {{%\\w+}} [[ext]] Fma [[lx]] [[ly]] [[la]]\n" +
+           "; CHECK: OpStore {{%\\w+}} [[fma]]\n" +
+           "%main = OpFunction %void None %void_func\n" +
+           "%main_lab = OpLabel\n" +
+           "%x = OpVariable %_ptr_float Function\n" +
+           "%y = OpVariable %_ptr_float Function\n" +
+           "%a = OpVariable %_ptr_float Function\n" +
+           "%lx = OpLoad %float %x\n" +
+           "%ly = OpLoad %float %y\n" +
+           "%mul = OpFMul %float %lx %ly\n" +
+           "%la = OpLoad %float %a\n" +
+           "%3 = OpFAdd %float %mul %la\n" +
+           "OpStore %a %3\n" +
+           "OpReturn\n" +
+           "OpFunctionEnd",
+       3, true),
+    // Test case 1:  a + (x * y) = Fma(x, y, a)
+   InstructionFoldingCase<bool>(
+       Header() +
+           "; CHECK: [[ext:%\\w+]] = OpExtInstImport \"GLSL.std.450\"\n" +
+           "; CHECK: OpFunction\n" +
+           "; CHECK: [[x:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[y:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[a:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[lx:%\\w+]] = OpLoad {{%\\w+}} [[x]]\n" +
+           "; CHECK: [[ly:%\\w+]] = OpLoad {{%\\w+}} [[y]]\n" +
+           "; CHECK: [[la:%\\w+]] = OpLoad {{%\\w+}} [[a]]\n" +
+           "; CHECK: [[fma:%\\w+]] = OpExtInst {{%\\w+}} [[ext]] Fma [[lx]] [[ly]] [[la]]\n" +
+           "; CHECK: OpStore {{%\\w+}} [[fma]]\n" +
+           "%main = OpFunction %void None %void_func\n" +
+           "%main_lab = OpLabel\n" +
+           "%x = OpVariable %_ptr_float Function\n" +
+           "%y = OpVariable %_ptr_float Function\n" +
+           "%a = OpVariable %_ptr_float Function\n" +
+           "%lx = OpLoad %float %x\n" +
+           "%ly = OpLoad %float %y\n" +
+           "%mul = OpFMul %float %lx %ly\n" +
+           "%la = OpLoad %float %a\n" +
+           "%3 = OpFAdd %float %la %mul\n" +
+           "OpStore %a %3\n" +
+           "OpReturn\n" +
+           "OpFunctionEnd",
+       3, true),
+   // Test case 2: (x * y) + a = Fma(x, y, a) with vectors
+   InstructionFoldingCase<bool>(
+       Header() +
+           "; CHECK: [[ext:%\\w+]] = OpExtInstImport \"GLSL.std.450\"\n" +
+           "; CHECK: OpFunction\n" +
+           "; CHECK: [[x:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[y:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[a:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[lx:%\\w+]] = OpLoad {{%\\w+}} [[x]]\n" +
+           "; CHECK: [[ly:%\\w+]] = OpLoad {{%\\w+}} [[y]]\n" +
+           "; CHECK: [[la:%\\w+]] = OpLoad {{%\\w+}} [[a]]\n" +
+           "; CHECK: [[fma:%\\w+]] = OpExtInst {{%\\w+}} [[ext]] Fma [[lx]] [[ly]] [[la]]\n" +
+           "; CHECK: OpStore {{%\\w+}} [[fma]]\n" +
+           "%main = OpFunction %void None %void_func\n" +
+           "%main_lab = OpLabel\n" +
+           "%x = OpVariable %_ptr_v4float Function\n" +
+           "%y = OpVariable %_ptr_v4float Function\n" +
+           "%a = OpVariable %_ptr_v4float Function\n" +
+           "%lx = OpLoad %v4float %x\n" +
+           "%ly = OpLoad %v4float %y\n" +
+           "%mul = OpFMul %v4float %lx %ly\n" +
+           "%la = OpLoad %v4float %a\n" +
+           "%3 = OpFAdd %v4float %mul %la\n" +
+           "OpStore %a %3\n" +
+           "OpReturn\n" +
+           "OpFunctionEnd",
+       3, true),
+    // Test case 3:  a + (x * y) = Fma(x, y, a) with vectors
+   InstructionFoldingCase<bool>(
+       Header() +
+           "; CHECK: [[ext:%\\w+]] = OpExtInstImport \"GLSL.std.450\"\n" +
+           "; CHECK: OpFunction\n" +
+           "; CHECK: [[x:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[y:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[a:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[lx:%\\w+]] = OpLoad {{%\\w+}} [[x]]\n" +
+           "; CHECK: [[ly:%\\w+]] = OpLoad {{%\\w+}} [[y]]\n" +
+           "; CHECK: [[la:%\\w+]] = OpLoad {{%\\w+}} [[a]]\n" +
+           "; CHECK: [[fma:%\\w+]] = OpExtInst {{%\\w+}} [[ext]] Fma [[lx]] [[ly]] [[la]]\n" +
+           "; CHECK: OpStore {{%\\w+}} [[fma]]\n" +
+           "%main = OpFunction %void None %void_func\n" +
+           "%main_lab = OpLabel\n" +
+           "%x = OpVariable %_ptr_float Function\n" +
+           "%y = OpVariable %_ptr_float Function\n" +
+           "%a = OpVariable %_ptr_float Function\n" +
+           "%lx = OpLoad %float %x\n" +
+           "%ly = OpLoad %float %y\n" +
+           "%mul = OpFMul %float %lx %ly\n" +
+           "%la = OpLoad %float %a\n" +
+           "%3 = OpFAdd %float %la %mul\n" +
+           "OpStore %a %3\n" +
+           "OpReturn\n" +
+           "OpFunctionEnd",
+       3, true),
+    // Test 5: that the OpExtInstImport instruction is generated if it is missing.
+   InstructionFoldingCase<bool>(
+           std::string() +
+           "; CHECK: [[ext:%\\w+]] = OpExtInstImport \"GLSL.std.450\"\n" +
+           "; CHECK: OpFunction\n" +
+           "; CHECK: [[x:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[y:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[a:%\\w+]] = OpVariable {{%\\w+}} Function\n" +
+           "; CHECK: [[lx:%\\w+]] = OpLoad {{%\\w+}} [[x]]\n" +
+           "; CHECK: [[ly:%\\w+]] = OpLoad {{%\\w+}} [[y]]\n" +
+           "; CHECK: [[la:%\\w+]] = OpLoad {{%\\w+}} [[a]]\n" +
+           "; CHECK: [[fma:%\\w+]] = OpExtInst {{%\\w+}} [[ext]] Fma [[lx]] [[ly]] [[la]]\n" +
+           "; CHECK: OpStore {{%\\w+}} [[fma]]\n" +
+           "OpCapability Shader\n" +
+           "OpMemoryModel Logical GLSL450\n" +
+           "OpEntryPoint Fragment %main \"main\"\n" +
+           "OpExecutionMode %main OriginUpperLeft\n" +
+           "OpSource GLSL 140\n" +
+           "OpName %main \"main\"\n" +
+           "%void = OpTypeVoid\n" +
+           "%void_func = OpTypeFunction %void\n" +
+           "%bool = OpTypeBool\n" +
+           "%float = OpTypeFloat 32\n" +
+           "%_ptr_float = OpTypePointer Function %float\n" +
+           "%main = OpFunction %void None %void_func\n" +
+           "%main_lab = OpLabel\n" +
+           "%x = OpVariable %_ptr_float Function\n" +
+           "%y = OpVariable %_ptr_float Function\n" +
+           "%a = OpVariable %_ptr_float Function\n" +
+           "%lx = OpLoad %float %x\n" +
+           "%ly = OpLoad %float %y\n" +
+           "%mul = OpFMul %float %lx %ly\n" +
+           "%la = OpLoad %float %a\n" +
+           "%3 = OpFAdd %float %mul %la\n" +
+           "OpStore %a %3\n" +
+           "OpReturn\n" +
+           "OpFunctionEnd",
+       3, true),
+   // Test 5: Don't fold if the multiple is marked no contract.
+   InstructionFoldingCase<bool>(
+       std::string() +
+           "OpCapability Shader\n" +
+           "OpMemoryModel Logical GLSL450\n" +
+           "OpEntryPoint Fragment %main \"main\"\n" +
+           "OpExecutionMode %main OriginUpperLeft\n" +
+           "OpSource GLSL 140\n" +
+           "OpName %main \"main\"\n" +
+           "OpDecorate %mul NoContraction\n" +
+           "%void = OpTypeVoid\n" +
+           "%void_func = OpTypeFunction %void\n" +
+           "%bool = OpTypeBool\n" +
+           "%float = OpTypeFloat 32\n" +
+           "%_ptr_float = OpTypePointer Function %float\n" +
+           "%main = OpFunction %void None %void_func\n" +
+           "%main_lab = OpLabel\n" +
+           "%x = OpVariable %_ptr_float Function\n" +
+           "%y = OpVariable %_ptr_float Function\n" +
+           "%a = OpVariable %_ptr_float Function\n" +
+           "%lx = OpLoad %float %x\n" +
+           "%ly = OpLoad %float %y\n" +
+           "%mul = OpFMul %float %lx %ly\n" +
+           "%la = OpLoad %float %a\n" +
+           "%3 = OpFAdd %float %mul %la\n" +
+           "OpStore %a %3\n" +
+           "OpReturn\n" +
+           "OpFunctionEnd",
+       3, false),
+       // Test 6: Don't fold if the add is marked no contract.
+       InstructionFoldingCase<bool>(
+           std::string() +
+               "OpCapability Shader\n" +
+               "OpMemoryModel Logical GLSL450\n" +
+               "OpEntryPoint Fragment %main \"main\"\n" +
+               "OpExecutionMode %main OriginUpperLeft\n" +
+               "OpSource GLSL 140\n" +
+               "OpName %main \"main\"\n" +
+               "OpDecorate %3 NoContraction\n" +
+               "%void = OpTypeVoid\n" +
+               "%void_func = OpTypeFunction %void\n" +
+               "%bool = OpTypeBool\n" +
+               "%float = OpTypeFloat 32\n" +
+               "%_ptr_float = OpTypePointer Function %float\n" +
+               "%main = OpFunction %void None %void_func\n" +
+               "%main_lab = OpLabel\n" +
+               "%x = OpVariable %_ptr_float Function\n" +
+               "%y = OpVariable %_ptr_float Function\n" +
+               "%a = OpVariable %_ptr_float Function\n" +
+               "%lx = OpLoad %float %x\n" +
+               "%ly = OpLoad %float %y\n" +
+               "%mul = OpFMul %float %lx %ly\n" +
+               "%la = OpLoad %float %a\n" +
+               "%3 = OpFAdd %float %mul %la\n" +
+               "OpStore %a %3\n" +
+               "OpReturn\n" +
+               "OpFunctionEnd",
+           3, false)
+));
+
 using MatchingInstructionWithNoResultFoldingTest =
 ::testing::TestWithParam<InstructionFoldingCase<bool>>;