Merge pull request #3514 from martin-frbg/issue3513

Fix ?LASWP pivot index calculation for negative increments other than -1

lapack/laswp/generic/laswp_k_1.c

@@ -57,10 +57,9 @@ int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT *a, BLASLONG
   a--;
   k1 --;
 
-#ifndef MINUS
  ipiv += k1;
-#else
-  ipiv -= (k2 - 1) * incx;
+#ifdef MINUS
+  ipiv -= (k2 - k1 - 1) * incx;
 #endif
 
   if (n  <= 0) return 0;

lapack/laswp/generic/laswp_k_2.c

@@ -59,10 +59,9 @@ int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT *a, BLASLONG
   a--;
   k1 --;
 
-#ifndef MINUS
  ipiv += k1;
-#else
-  ipiv -= (k2 - 1) * incx;
+#ifdef MINUS
+  ipiv -= (k2 - k1 - 1) * incx;
 #endif
 
   if (n  <= 0) return 0;

lapack/laswp/generic/laswp_k_4.c

@@ -65,10 +65,9 @@ int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT *a, BLASLONG
   a--;
   k1 --;
 
-#ifndef MINUS
  ipiv += k1;
-#else
-  ipiv -= (k2 - 1) * incx;
+#ifdef MINUS
+  ipiv -= (k2 - k1 - 1) * incx;
 #endif
 
   if (n  <= 0) return 0;

lapack/laswp/generic/laswp_k_8.c

@@ -78,10 +78,9 @@ int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT *a, BLASLONG
   a--;
   k1 --;
 
-#ifndef MINUS
   ipiv += k1;
-#else
-  ipiv -= (k2 - 1) * incx;
+#ifdef MINUS
+  ipiv -= (k2 - k1 - 1) * incx;
 #endif
 
   if (n  <= 0) return 0;

lapack/laswp/generic/zlaswp_k_1.c

@@ -59,10 +59,9 @@ int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT dummy4,
   lda *= 2;
   k1 --;
 
-#ifndef MINUS
  ipiv += k1;
-#else
-  ipiv -= (k2 - 1) * incx;
+#ifdef MINUS
+  ipiv -= (k2 - k1 - 1) * incx;
 #endif
 
   if (n  <= 0) return 0;

lapack/laswp/generic/zlaswp_k_2.c

@@ -60,10 +60,9 @@ int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT dummy4,
   lda *= 2;
   k1 --;
 
-#ifndef MINUS
  ipiv += k1;
-#else
-  ipiv -= (k2 - 1) * incx;
+#ifdef MINUS
+  ipiv -= (k2 - k1 - 1) * incx;
 #endif
 
   if (n  <= 0) return 0;

lapack/laswp/generic/zlaswp_k_4.c

@@ -69,10 +69,9 @@ int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT dummy4,
   lda *= 2;
   k1 --;
 
-#ifndef MINUS
  ipiv += k1;
-#else
-  ipiv -= (k2 - 1) * incx;
+#ifdef MINUS
+  ipiv -= (k2 - k1 - 1) * incx;
 #endif
 
   if (n  <= 0) return 0;