1 files changed, 15 insertions, 1 deletions
diff --git a/llvm/lib/Target/SPIRV/SPIRVUtils.cpp b/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
index 820e56b..327c011 100644
--- a/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
@@ -181,7 +181,7 @@ void buildOpMemberDecorate(Register Reg, MachineInstr &I,
 }
 
 void buildOpSpirvDecorations(Register Reg, MachineIRBuilder &MIRBuilder,
-                             const MDNode *GVarMD) {
+                             const MDNode *GVarMD, const SPIRVSubtarget &ST) {
   for (unsigned I = 0, E = GVarMD->getNumOperands(); I != E; ++I) {
     auto *OpMD = dyn_cast<MDNode>(GVarMD->getOperand(I));
     if (!OpMD)
@@ -193,6 +193,20 @@ void buildOpSpirvDecorations(Register Reg, MachineIRBuilder &MIRBuilder,
     if (!DecorationId)
       report_fatal_error("Expect SPIR-V <Decoration> operand to be the first "
                          "element of the decoration");
+
+    // The goal of `spirv.Decorations` metadata is to provide a way to
+    // represent SPIR-V entities that do not map to LLVM in an obvious way.
+    // FP flags do have obvious matches between LLVM IR and SPIR-V.
+    // Additionally, we have no guarantee at this point that the flags passed
+    // through the decoration are not violated already in the optimizer passes.
+    // Therefore, we simply ignore FP flags, including NoContraction, and
+    // FPFastMathMode.
+    if (DecorationId->getZExtValue() ==
+            static_cast<uint32_t>(SPIRV::Decoration::NoContraction) ||
+        DecorationId->getZExtValue() ==
+            static_cast<uint32_t>(SPIRV::Decoration::FPFastMathMode)) {
+      continue; // Ignored.
+    }
     auto MIB = MIRBuilder.buildInstr(SPIRV::OpDecorate)
                    .addUse(Reg)
                    .addImm(static_cast<uint32_t>(DecorationId->getZExtValue()));