[flang-commits] [flang] [mlir] [MLIR][OpenMP] Fix type mismatch in linear clause for INTEGER(8) variables (PR #173982)

[Krzysztof Parzyszek via flang-commits]

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@@ -187,17 +187,45 @@ class LinearClauseProcessor {
                        llvm::Value *loopInductionVar) {
     builder.SetInsertPoint(loopBody->getTerminator());
     for (size_t index = 0; index < linearPreconditionVars.size(); index++) {
-      // Emit increments for linear vars
-      llvm::LoadInst *linearVarStart = builder.CreateLoad(
-          linearVarTypes[index], linearPreconditionVars[index]);
-      auto mulInst = builder.CreateMul(loopInductionVar, linearSteps[index]);
-      if (linearVarTypes[index]->isIntegerTy()) {
-        auto addInst = builder.CreateAdd(linearVarStart, mulInst);
+      llvm::Type *linearVarType = linearVarTypes[index];
+      llvm::Value *iv = loopInductionVar;
+      llvm::Value *step = linearSteps[index];
+
+      // Helper to cast signed integers with sign extension or truncation
+      auto castSignedInt = [&](llvm::Value *val,
+                               llvm::Type *targetType) -> llvm::Value * {
+        if (val->getType() == targetType)
+          return val;
+        return builder.CreateSExtOrTrunc(val, targetType);
+      };
+
+      if (linearVarType->isIntegerTy()) {
+        // Integer path: normalize all arithmetic to linearVarType
+        iv = castSignedInt(iv, linearVarType);
+        step = castSignedInt(step, linearVarType);
+
+        llvm::LoadInst *linearVarStart =
+            builder.CreateLoad(linearVarType, linearPreconditionVars[index]);
+        llvm::Value *mulInst = builder.CreateMul(iv, step);
+        llvm::Value *addInst = builder.CreateAdd(linearVarStart, mulInst);
         builder.CreateStore(addInst, linearLoopBodyTemps[index]);
-      } else if (linearVarTypes[index]->isFloatingPointTy()) {
-        auto cvt = builder.CreateSIToFP(mulInst, linearVarTypes[index]);
-        auto addInst = builder.CreateFAdd(linearVarStart, cvt);
+      } else if (linearVarType->isFloatingPointTy()) {
+        // Float path: perform multiply in integer, then convert to float
+        llvm::Type *ivType = iv->getType();
+        if (!ivType->isIntegerTy())
+          llvm_unreachable("OpenMP loop induction variable must be an integer "
+                           "type when updating floating-point linear vars");
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kparzysz wrote:

If this is a legitimate concern, it should be checked in both cases.

https://github.com/llvm/llvm-project/pull/173982