[TOSA] Fix negate maxValue computation (llvm#126295)

getInput1Zp() returns an unsigned value which means in case of negative
zero point value the max intermediate value computation currently goes
wrong. Use getInput1ZpAttr() instead which returns an APInt and allows
easy sign extension to int64_t.

Author: RoboTux

mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp

@@ -146,11 +146,13 @@ static Value createLinalgBodyCalculationForElementwiseOp(
       return rewriter.create<arith::NegFOp>(loc, resultTypes, args);
 
     if (isa<IntegerType>(elementTy)) {
-      auto inputZpAttr = cast<tosa::NegateOp>(op).getInput1Zp();
-      auto outputZpAttr = cast<tosa::NegateOp>(op).getOutputZp();
+      auto inputZpAttr = cast<tosa::NegateOp>(op).getInput1ZpAttr();
+      auto outputZpAttr = cast<tosa::NegateOp>(op).getOutputZpAttr();
 
-      const int64_t inZp = inputZpAttr ? *inputZpAttr : 0;
-      const int64_t outZp = outputZpAttr ? *outputZpAttr : 0;
+      const int64_t inZp =
+          inputZpAttr ? inputZpAttr.getValue().getSExtValue() : 0;
+      const int64_t outZp =
+          outputZpAttr ? outputZpAttr.getValue().getSExtValue() : 0;
 
       if (!inZp && !outZp) {
         auto constant = rewriter.create<arith::ConstantOp>(

mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir

@@ -911,12 +911,25 @@ func.func @test_negate_quantized(%arg0: tensor<1xi8>) -> () {
   // CHECK: linalg.yield [[TRUNC]]
   %2 = tosa.negate %arg0 {input1_zp = 32640 : i32, output_zp = 0 : i32} : (tensor<1xi8>) -> tensor<1xi8>
 
+  // CHECK: linalg.generic
+  // CHECK: ^bb0(%[[BBARG0:.+]]: i8,
+  // CHECK: [[C_128:%.+]] = arith.constant -128
+  // CHECK: [[EXT:%.+]] = arith.extsi %[[BBARG0]] : i8 to i16
+  // CHECK: [[SUB:%.+]] = arith.subi [[C_128]], [[EXT]]
+  // CHECK: [[MIN:%.+]] = arith.constant -128
+  // CHECK: [[MAX:%.+]] = arith.constant 127
+  // CHECK: [[LBOUND:%.+]] = arith.maxsi [[MIN]], [[SUB]]
+  // CHECK: [[UBOUND:%.+]] = arith.minsi [[MAX]], [[LBOUND]]
+  // CHECK: [[TRUNC:%.+]] = arith.trunci [[UBOUND]]
+  // CHECK: linalg.yield [[TRUNC]]
+  %3 = tosa.negate %arg0 {input1_zp = -128 : i32, output_zp = 0 : i32} : (tensor<1xi8>) -> tensor<1xi8>
+
   // CHECK: linalg.generic
   // CHECK: ^bb0(%[[BBARG0:.+]]: i8,
   // CHECK: [[ZERO:%.+]] = arith.constant 0
   // CHECK: [[SUB:%.+]] = arith.subi [[ZERO]],
   // CHECK: linalg.yield [[SUB]]
-  %3 = tosa.negate %arg0 {quantization_info = #tosa.unary_quant<input_zp = 0, output_zp = 0>} : (tensor<1xi8>) -> tensor<1xi8>
+  %4 = tosa.negate %arg0 {quantization_info = #tosa.unary_quant<input_zp = 0, output_zp = 0>} : (tensor<1xi8>) -> tensor<1xi8>
 
   return
 }