From 5ffbe646e12fe76682410674f5de4146c87aa973 Mon Sep 17 00:00:00 2001
From: Angelika Schwarz <17718454+angsch@users.noreply.github.com>
Date: Sat, 11 Nov 2023 09:19:48 +0100
Subject: [PATCH] Improve matcopy interface

* rows = 0 or cols = 0 is now a legal input and
  takes quick return path
* Follow BLAS/LAPACK convention that the leading
  dimensions must be at least 1.
---
 interface/imatcopy.c  | 22 ++++++++++++----------
 interface/omatcopy.c  | 22 ++++++++++++----------
 interface/zimatcopy.c | 30 ++++++++++++++++--------------
 interface/zomatcopy.c | 30 ++++++++++++++++--------------
 4 files changed, 56 insertions(+), 48 deletions(-)

diff --git a/interface/imatcopy.c b/interface/imatcopy.c
index 4cf0966cc8..6a1ad282c0 100644
--- a/interface/imatcopy.c
+++ b/interface/imatcopy.c
@@ -100,27 +100,29 @@ void CNAME( enum CBLAS_ORDER CORDER, enum CBLAS_TRANSPOSE CTRANS, blasint crows,
 
 	if ( order == BlasColMajor)
 	{
-        	if ( trans == BlasNoTrans  &&  *ldb < *rows ) info = 8;
-        	if ( trans == BlasTrans    &&  *ldb < *cols ) info = 8;
+        	if ( trans == BlasNoTrans  &&  *ldb < MAX(1,*rows) ) info = 8;
+        	if ( trans == BlasTrans    &&  *ldb < MAX(1,*cols) ) info = 8;
 	}
 	if ( order == BlasRowMajor)
 	{
-        	if ( trans == BlasNoTrans  &&  *ldb < *cols ) info = 8;
-        	if ( trans == BlasTrans    &&  *ldb < *rows ) info = 8;
+        	if ( trans == BlasNoTrans  &&  *ldb < MAX(1,*cols) ) info = 8;
+        	if ( trans == BlasTrans    &&  *ldb < MAX(1,*rows) ) info = 8;
 	}
 
-	if ( order == BlasColMajor &&  *lda < *rows ) info = 7;
-	if ( order == BlasRowMajor &&  *lda < *cols ) info = 7;
-	if ( *cols <= 0 ) info = 4;
-	if ( *rows <= 0 ) info = 3;
-	if ( trans < 0  ) info = 2;
-	if ( order < 0  ) info = 1;
+	if ( order == BlasColMajor &&  *lda < MAX(1,*rows) ) info = 7;
+	if ( order == BlasRowMajor &&  *lda < MAX(1,*cols) ) info = 7;
+	if ( *cols < 0 ) info = 4;
+	if ( *rows < 0 ) info = 3;
+	if ( trans < 0 ) info = 2;
+	if ( order < 0 ) info = 1;
 
 	if (info >= 0) {
     		BLASFUNC(xerbla)(ERROR_NAME, &info, sizeof(ERROR_NAME));
     		return;
   	}
 
+	if ((*rows == 0) || (*cols == 0)) return;
+
 #ifdef NEW_IMATCOPY
     if ( *lda == *ldb ) {
         if ( order == BlasColMajor )
diff --git a/interface/omatcopy.c b/interface/omatcopy.c
index 59650cfa09..c26446f5c0 100644
--- a/interface/omatcopy.c
+++ b/interface/omatcopy.c
@@ -90,27 +90,29 @@ void CNAME(enum CBLAS_ORDER CORDER, enum CBLAS_TRANSPOSE CTRANS, blasint crows,
 #endif
 	if ( order == BlasColMajor)
 	{
-        	if ( trans == BlasNoTrans  &&  *ldb < *rows ) info = 9;
-        	if ( trans == BlasTrans    &&  *ldb < *cols ) info = 9;
+        	if ( trans == BlasNoTrans  &&  *ldb < MAX(1,*rows) ) info = 9;
+        	if ( trans == BlasTrans    &&  *ldb < MAX(1,*cols) ) info = 9;
 	}
 	if ( order == BlasRowMajor)
 	{
-        	if ( trans == BlasNoTrans  &&  *ldb < *cols ) info = 9;
-        	if ( trans == BlasTrans    &&  *ldb < *rows ) info = 9;
+        	if ( trans == BlasNoTrans  &&  *ldb < MAX(1,*cols) ) info = 9;
+        	if ( trans == BlasTrans    &&  *ldb < MAX(1,*rows) ) info = 9;
 	}
 
-	if ( order == BlasColMajor &&  *lda < *rows ) info = 7;
-	if ( order == BlasRowMajor &&  *lda < *cols ) info = 7;
-	if ( *cols <= 0 ) info = 4;
-	if ( *rows <= 0 ) info = 3;
-	if ( trans < 0  ) info = 2;
-	if ( order < 0  ) info = 1;
+	if ( order == BlasColMajor &&  *lda < MAX(1,*rows) ) info = 7;
+	if ( order == BlasRowMajor &&  *lda < MAX(1,*cols) ) info = 7;
+	if ( *cols < 0 ) info = 4;
+	if ( *rows < 0 ) info = 3;
+	if ( trans < 0 ) info = 2;
+	if ( order < 0 ) info = 1;
 
 	if (info >= 0) {
     		BLASFUNC(xerbla)(ERROR_NAME, &info, sizeof(ERROR_NAME));
     		return;
   	}
 
+	if ((*rows == 0) || (*cols == 0)) return;
+
 	if ( order == BlasColMajor )
 	{
 		if ( trans == BlasNoTrans )
diff --git a/interface/zimatcopy.c b/interface/zimatcopy.c
index b0b32dc87b..b66489eb72 100644
--- a/interface/zimatcopy.c
+++ b/interface/zimatcopy.c
@@ -101,31 +101,33 @@ void CNAME( enum CBLAS_ORDER CORDER, enum CBLAS_TRANSPOSE CTRANS, blasint crows,
 
 	if ( order == BlasColMajor)
 	{
-        	if ( trans == BlasNoTrans      &&  *ldb < *rows ) info = 9;
-        	if ( trans == BlasConj         &&  *ldb < *rows ) info = 9;
-        	if ( trans == BlasTrans        &&  *ldb < *cols ) info = 9;
-        	if ( trans == BlasTransConj    &&  *ldb < *cols ) info = 9;
+        	if ( trans == BlasNoTrans      &&  *ldb < MAX(1,*rows) ) info = 9;
+        	if ( trans == BlasConj         &&  *ldb < MAX(1,*rows) ) info = 9;
+        	if ( trans == BlasTrans        &&  *ldb < MAX(1,*cols) ) info = 9;
+        	if ( trans == BlasTransConj    &&  *ldb < MAX(1,*cols) ) info = 9;
 	}
 	if ( order == BlasRowMajor)
 	{
-        	if ( trans == BlasNoTrans    &&  *ldb < *cols ) info = 9;
-        	if ( trans == BlasConj       &&  *ldb < *cols ) info = 9;
-        	if ( trans == BlasTrans      &&  *ldb < *rows ) info = 9;
-        	if ( trans == BlasTransConj  &&  *ldb < *rows ) info = 9;
+        	if ( trans == BlasNoTrans    &&  *ldb < MAX(1,*cols) ) info = 9;
+        	if ( trans == BlasConj       &&  *ldb < MAX(1,*cols) ) info = 9;
+        	if ( trans == BlasTrans      &&  *ldb < MAX(1,*rows) ) info = 9;
+        	if ( trans == BlasTransConj  &&  *ldb < MAX(1,*rows) ) info = 9;
 	}
 
-	if ( order == BlasColMajor &&  *lda < *rows ) info = 7;
-	if ( order == BlasRowMajor &&  *lda < *cols ) info = 7;
-	if ( *cols <= 0 ) info = 4;
-	if ( *rows <= 0 ) info = 3;
-	if ( trans < 0  ) info = 2;
-	if ( order < 0  ) info = 1;
+	if ( order == BlasColMajor &&  *lda < MAX(1,*rows) ) info = 7;
+	if ( order == BlasRowMajor &&  *lda < MAX(1,*cols) ) info = 7;
+	if ( *cols < 0 ) info = 4;
+	if ( *rows < 0 ) info = 3;
+	if ( trans < 0 ) info = 2;
+	if ( order < 0 ) info = 1;
 
 	if (info >= 0) {
     		BLASFUNC(xerbla)(ERROR_NAME, &info, sizeof(ERROR_NAME));
     		return;
   	}
 
+	if ((*rows == 0) || (*cols == 0)) return;
+
 #ifdef NEW_IMATCOPY
     if (*lda == *ldb ) {
         if ( order == BlasColMajor )
diff --git a/interface/zomatcopy.c b/interface/zomatcopy.c
index 7345633a20..7121711d87 100644
--- a/interface/zomatcopy.c
+++ b/interface/zomatcopy.c
@@ -92,31 +92,33 @@ void CNAME(enum CBLAS_ORDER CORDER, enum CBLAS_TRANSPOSE CTRANS, blasint crows,
 #endif
 	if ( order == BlasColMajor)
 	{
-        	if ( trans == BlasNoTrans      &&  *ldb < *rows ) info = 9;
-        	if ( trans == BlasConj         &&  *ldb < *rows ) info = 9;
-        	if ( trans == BlasTrans        &&  *ldb < *cols ) info = 9;
-        	if ( trans == BlasTransConj    &&  *ldb < *cols ) info = 9;
+        	if ( trans == BlasNoTrans      &&  *ldb < MAX(1,*rows) ) info = 9;
+        	if ( trans == BlasConj         &&  *ldb < MAX(1,*rows) ) info = 9;
+        	if ( trans == BlasTrans        &&  *ldb < MAX(1,*cols) ) info = 9;
+        	if ( trans == BlasTransConj    &&  *ldb < MAX(1,*cols) ) info = 9;
 	}
 	if ( order == BlasRowMajor)
 	{
-        	if ( trans == BlasNoTrans    &&  *ldb < *cols ) info = 9;
-        	if ( trans == BlasConj       &&  *ldb < *cols ) info = 9;
-        	if ( trans == BlasTrans      &&  *ldb < *rows ) info = 9;
-        	if ( trans == BlasTransConj  &&  *ldb < *rows ) info = 9;
+        	if ( trans == BlasNoTrans    &&  *ldb < MAX(1,*cols) ) info = 9;
+        	if ( trans == BlasConj       &&  *ldb < MAX(1,*cols) ) info = 9;
+        	if ( trans == BlasTrans      &&  *ldb < MAX(1,*rows) ) info = 9;
+        	if ( trans == BlasTransConj  &&  *ldb < MAX(1,*rows) ) info = 9;
 	}
 
-	if ( order == BlasColMajor &&  *lda < *rows ) info = 7;
-	if ( order == BlasRowMajor &&  *lda < *cols ) info = 7;
-	if ( *cols <= 0 ) info = 4;
-	if ( *rows <= 0 ) info = 3;
-	if ( trans < 0  ) info = 2;
-	if ( order < 0  ) info = 1;
+	if ( order == BlasColMajor &&  *lda < MAX(1,*rows) ) info = 7;
+	if ( order == BlasRowMajor &&  *lda < MAX(1,*cols) ) info = 7;
+	if ( *cols < 0 ) info = 4;
+	if ( *rows < 0 ) info = 3;
+	if ( trans < 0 ) info = 2;
+	if ( order < 0 ) info = 1;
 
 	if (info >= 0) {
     		BLASFUNC(xerbla)(ERROR_NAME, &info, sizeof(ERROR_NAME));
     		return;
   	}
 
+	if ((*rows == 0) || (*cols == 0)) return;
+
 	if ( order == BlasColMajor )
 	{