Correct issue ARM-software#172 : singular matrix inversion

Author: christophe0606

Source/MatrixFunctions/arm_mat_inverse_f16.c

@@ -155,6 +155,9 @@ arm_status arm_mat_inverse_f16(
     /* Index modifier to navigate through the columns */
     for(column = 0U; column < numCols; column++)
     {
+      /* reset flag */
+      flag = 0; 
+      
       /* Check if the pivot element is zero..
        * If it is zero then interchange the row with non zero row below.
        * If there is no non zero element to replace in the rows below,

Source/MatrixFunctions/arm_mat_inverse_f32.c

@@ -188,6 +188,9 @@ arm_status arm_mat_inverse_f32(
     /* Index modifier to navigate through the columns */
     for(column = 0U; column < numCols; column++)
     {
+      /* reset flag */
+      flag = 0; 
+      
       /* Check if the pivot element is zero..
        * If it is zero then interchange the row with non zero row below.
        * If there is no non zero element to replace in the rows below,

Source/MatrixFunctions/arm_mat_inverse_f64.c

@@ -153,6 +153,9 @@ arm_status arm_mat_inverse_f64(
     /* Index modifier to navigate through the columns */
     for(column = 0U; column < numCols; column++)
     {
+      /* reset flag */
+      flag = 0; 
+      
       /* Check if the pivot element is zero..
        * If it is zero then interchange the row with non zero row below.
        * If there is no non zero element to replace in the rows below,

Testing/PatternGeneration/Matrix.py

@@ -806,6 +806,15 @@ def writeUnaryTests(config,format):
     r = np.linalg.inv(ma)
     vals = vals + list(r.reshape(4))
     dims.append(2)
+
+    # Add matrix for testing singular matrix
+
+    ma = np.array([[1., 2.], [2., 4.]])
+    inp = inp + list(ma.reshape(4))
+
+    r = np.array([0.,0.5,1.0,-0.5])
+    vals = vals + list(r)
+    dims.append(2)
     #
     config.writeInputS16(1, dims,"DimsInvert")
     config.writeInput(1, inp,"InputInvert")
@@ -1197,9 +1206,9 @@ def generatePatterns():
     configUnaryq15.setOverwrite(False)
     configUnaryq7.setOverwrite(False)
 
-    #writeUnaryTests(configUnaryf64,Tools.F64)
-    #writeUnaryTests(configUnaryf32,Tools.F32)
-    #writeUnaryTests(configUnaryf16,Tools.F16)
+    writeUnaryTests(configUnaryf64,Tools.F64)
+    writeUnaryTests(configUnaryf32,Tools.F32)
+    writeUnaryTests(configUnaryf16,Tools.F16)
     #writeUnaryTests(configUnaryq31,Tools.Q31)
     #writeUnaryTests(configUnaryq31,Tools.Q31)
     #writeUnaryTests(configUnaryq15,Tools.Q15)

Testing/Patterns/DSP/Matrix/Unary/UnaryF16/DimsInvert1_s16.txt

@@ -1,5 +1,5 @@
 H
-10
+11
 // 1
 0x0001
 // 2
@@ -20,3 +20,5 @@ H
 0x0010
 // 2
 0x0002
+// 2
+0x0002

Testing/Patterns/DSP/Matrix/Unary/UnaryF16/InputInvert1_f16.txt

@@ -1,5 +1,5 @@
 H
-709
+713
 // 0.500000
 0x3800
 // 0.707107
@@ -1418,3 +1418,11 @@ H
 0x4400
 // 5.000000
 0x4500
+// 1.000000
+0x3c00
+// 2.000000
+0x4000
+// 2.000000
+0x4000
+// 4.000000
+0x4400

Testing/Patterns/DSP/Matrix/Unary/UnaryF16/RefInvert1_f16.txt

@@ -1,5 +1,5 @@
 H
-709
+713
 // 2.000000
 0x4000
 // 0.707107
@@ -1418,3 +1418,11 @@ H
 0x3555
 // 0.000000
 0x0
+// 0.000000
+0x0
+// 0.500000
+0x3800
+// 1.000000
+0x3c00
+// -0.500000
+0xb800

Testing/Patterns/DSP/Matrix/Unary/UnaryF32/DimsInvert1_s16.txt

@@ -1,5 +1,5 @@
 H
-13
+14
 // 1
 0x0001
 // 2
@@ -26,3 +26,5 @@ H
 0x0021
 // 2
 0x0002
+// 2
+0x0002

Testing/Patterns/DSP/Matrix/Unary/UnaryF32/InputInvert1_f32.txt

@@ -1,5 +1,5 @@
 W
-3111
+3115
 // 0.500000
 0x3f000000
 // 0.707107
@@ -6222,3 +6222,11 @@ W
 0x40800000
 // 5.000000
 0x40a00000
+// 1.000000
+0x3f800000
+// 2.000000
+0x40000000
+// 2.000000
+0x40000000
+// 4.000000
+0x40800000

Testing/Patterns/DSP/Matrix/Unary/UnaryF32/RefInvert1_f32.txt

@@ -1,5 +1,5 @@
 W
-3111
+3115
 // 2.000000
 0x40000000
 // 0.707107
@@ -6222,3 +6222,11 @@ W
 0x3eaaaaab
 // 0.000000
 0x0
+// 0.000000
+0x0
+// 0.500000
+0x3f000000
+// 1.000000
+0x3f800000
+// -0.500000
+0xbf000000