Relax negative scales conditions in Quant Dialect (#61)

* relax negative scale conditions
* adapt tests now handling negative scales

Author: ZoranZomborat

mlir/lib/Dialect/Quant/IR/QuantTypes.cpp

@@ -330,11 +330,8 @@ LogicalResult UniformQuantizedType::verifyInvariants(
     return emitError() << "expressed type must be floating point";
 
   // Verify scale.
-  double minScale = getMinScale(expressedType);
-  double maxScale = getMaxScale(expressedType);
-  if (scale < minScale || scale > maxScale)
-    return emitError() << "scale out of expressed type range [" << minScale
-                       << ", " << maxScale << "]";
+  if (std::isinf(scale) || std::isnan(scale))
+    return emitError() << "illegal scale: " << scale;
 
   return success();
 }
@@ -398,12 +395,9 @@ LogicalResult UniformQuantizedPerAxisType::verifyInvariants(
                        << scales.size() << ", " << zeroPoints.size();
 
   // Verify scale.
-  double minScale = getMinScale(expressedType);
-  double maxScale = getMaxScale(expressedType);
   for (double scale : scales) {
-    if (scale < minScale || scale > maxScale)
-      return emitError() << "scale out of expressed type range [" << minScale
-                         << ", " << maxScale << "]";
+    if (std::isinf(scale) || std::isnan(scale))
+      return emitError() << "illegal scale: " << scale;
   }
 
   // Verify quantized dimension.

mlir/test/Dialect/Quant/parse-quantile-invalid.mlir

@@ -142,11 +142,6 @@ func.func @parse() -> !qalias {
 // expected-error@+1 {{expected non-function type}}
 !qalias = !quant.quantile<i8<-4:3>:f16:f33, {-1.0,1.0}:0.99872:127>
 
-// -----
-// Illegal scale: negative
-// expected-error@+1 {{scale out of expressed type range}}
-!qalias = !quant.quantile<i8<-4:3>:f16:f32, {-1.0,1.0}:-1.0:127>
-
 // -----
 // Illegal uniform params: missing quantized dimension
 // expected-error@+1 {{expected integer value}}

mlir/test/Dialect/Quant/parse-quantile.mlir

@@ -163,3 +163,21 @@ func.func @parse() -> !qalias {
   %0 = "foo"() : () -> !qalias
   return %0 : !qalias
 }
+
+// -----
+// Negative scale checking
+// CHECK: !quant.quantile<i4:f16:f32, {-1.000000e+00,-8.667000e-01,-7.333000e-01,-6.000000e-01,-4.667000e-01,-3.333000e-01,-2.000000e-01,-0.066699999999999995,0.066699999999999995,2.000000e-01,3.333000e-01,4.667000e-01,6.000000e-01,7.333000e-01,8.667000e-01,1.000000e+00}:-2.000000e+02>
+!qalias = !quant.quantile<i4:f16:f32, {-1.0000,-0.8667,-0.7333,-0.6000,-0.4667,-0.3333,-0.2000,-0.0667,0.0667,0.2000,0.3333,0.4667,0.6000,0.7333,0.8667,1.0000}:-2.0e+2>
+func.func @parse() -> !qalias {
+  %0 = "foo"() : () -> !qalias
+  return %0 : !qalias
+}
+
+// -----
+// Per-axis negative scale checking
+// CHECK: !quant.quantile<i4:f16:f32:1, {-1.000000e+00,-8.667000e-01,-7.333000e-01,-6.000000e-01,-4.667000e-01,-3.333000e-01,-2.000000e-01,-0.066699999999999995,0.066699999999999995,2.000000e-01,3.333000e-01,4.667000e-01,6.000000e-01,7.333000e-01,8.667000e-01,1.000000e+00}:{-2.000000e+02,-9.987200e-01:120}>
+!qalias = !quant.quantile<i4:f16:f32:1, {-1.0000,-0.8667,-0.7333,-0.6000,-0.4667,-0.3333,-0.2000,-0.0667,0.0667,0.2000,0.3333,0.4667,0.6000,0.7333,0.8667,1.0000}:{-2.0e+2,-0.99872:120}>
+func.func @parse() -> !qalias {
+  %0 = "foo"() : () -> !qalias
+  return %0 : !qalias
+}

mlir/test/Dialect/Quant/parse-uniform-invalid.mlir

@@ -125,11 +125,6 @@
 // expected-error@+1 {{expected non-function type}}
 !qalias = !quant.uniform<i8<-4:3>:f33, 0.99872:127>
 
-// -----
-// Illegal scale: negative
-// expected-error@+1 {{scale out of expressed type range}}
-!qalias = !quant.uniform<i8<-4:3>:f32, -1.0:127>
-
 // -----
 // Illegal uniform params: missing quantized dimension
 // expected-error@+1 {{expected integer value}}
@@ -141,27 +136,3 @@
 // expected-error@+1 {{expected floating point literal}}
 !qalias = !quant.uniform<i8<-4:3>:f32, {2.000000e+02,-19.987200e-01:1}>
 
-// -----
-// Illegal negative axis in per-axis quantization
-// expected-error@+1 {{illegal quantized dimension: -1}}
-!qalias = !quant.uniform<i8:f32:-1, {2.0,3.0:1}>
-
-// -----
-// Scale f16 underflow
-// expected-error@+1 {{scale out of expressed type range}}
-!qalias = !quant.uniform<i8:f16, 5.8e-8>
-
-// -----
-// Scale f16 overflow
-// expected-error@+1 {{scale out of expressed type range}}
-!qalias = !quant.uniform<i8:f16, 6.6e4>
-
-// -----
-// Scale f16 underflow in per-axis quantization
-// expected-error@+1 {{scale out of expressed type range}}
-!qalias = !quant.uniform<i8:f16:1, {2.0,5.8e-8}>
-
-// -----
-// Scale f16 overflow in per-axis quantization
-// expected-error@+1 {{scale out of expressed type range}}
-!qalias = !quant.uniform<i8:f16:1, {2.0,6.6e4}>

mlir/test/Dialect/Quant/parse-uniform.mlir

@@ -199,3 +199,21 @@ func.func @parse() -> !qalias {
   %0 = "foo"() : () -> !qalias
   return %0 : !qalias
 }
+
+// -----
+// Negative scale checking
+// CHECK: !quant.uniform<i8:f32, -2.000000e+02>
+!qalias = !quant.uniform<i8:f32, -2.0e+2>
+func.func @parse() -> !qalias {
+  %0 = "foo"() : () -> !qalias
+  return %0 : !qalias
+}
+
+// -----
+// Per axis negative scale checking
+// CHECK: !quant.uniform<i8:f32:1, {-2.000000e+02,-9.987200e-01:120}>
+!qalias = !quant.uniform<i8:f32:1, {-2.0e+2,-0.99872:120}>
+func.func @parse() -> !qalias {
+  %0 = "foo"() : () -> !qalias
+  return %0 : !qalias
+}