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

@@ -299,7 +299,7 @@ LogicalResult UniformQuantizedType::verify(
     return emitError() << "expressed type must be floating point";
 
   // Verify scale.
-  if (scale <= 0.0 || std::isinf(scale) || std::isnan(scale))
+  if (std::isinf(scale) || std::isnan(scale))
     return emitError() << "illegal scale: " << scale;
 
   return success();
@@ -364,7 +364,7 @@ LogicalResult UniformQuantizedPerAxisType::verify(
 
   // Verify scale.
   for (double scale : scales) {
-    if (scale <= 0.0 || std::isinf(scale) || std::isnan(scale))
+    if (std::isinf(scale) || std::isnan(scale))
       return emitError() << "illegal scale: " << scale;
   }
 

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 {{illegal scale: -1.000000}}
-!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 {{illegal scale: -1.000000}}
-!qalias = !quant.uniform<i8<-4:3>:f32, -1.0:127>
-
 // -----
 // Illegal uniform params: missing quantized dimension
 // expected-error@+1 {{expected integer value}}

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
+}