[Mlir-commits] [mlir] [TOSA] Fix negate maxValue computation (PR #126295)

[Thomas Preud'homme]

https://github.com/RoboTux updated https://github.com/llvm/llvm-project/pull/126295

>From 58e7545e40e9bd1b10849e5172687fa8e12c3e55 Mon Sep 17 00:00:00 2001
From: Thomas Preud'homme <thomas.preudhomme at arm.com>
Date: Fri, 7 Feb 2025 19:00:04 +0000
Subject: [PATCH 1/2] [TOSA] Fix negate maxValue computation

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.
---
 mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp |  8 ++++----
 .../Conversion/TosaToLinalg/tosa-to-linalg.mlir   | 15 ++++++++++++++-
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
index e4f055ea2f5c41b..de6a156ed3f5729 100644
--- a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
+++ b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
@@ -146,11 +146,11 @@ 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>(
diff --git a/mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir b/mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir
index 3031434e6d4ba1f..d8ba28a3ce8871d 100644
--- a/mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir
+++ b/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
 }

>From 6cba9c1935a5e42380cef7fd0b914bb30c8b0de2 Mon Sep 17 00:00:00 2001
From: Thomas Preud'homme <thomas.preudhomme at arm.com>
Date: Fri, 7 Feb 2025 20:55:55 +0000
Subject: [PATCH 2/2] Fix code formatting.

---
 mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
index de6a156ed3f5729..0246d9019368afd 100644
--- a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
+++ b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp
@@ -149,8 +149,10 @@ static Value createLinalgBodyCalculationForElementwiseOp(
       auto inputZpAttr = cast<tosa::NegateOp>(op).getInput1ZpAttr();
       auto outputZpAttr = cast<tosa::NegateOp>(op).getOutputZpAttr();
 
-      const int64_t inZp = inputZpAttr ? inputZpAttr.getValue().getSExtValue() : 0;
-      const int64_t outZp = outputZpAttr ? outputZpAttr.getValue().getSExtValue() : 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>(