diff --git a/config/armv7a/make_defs.mk b/config/armv7a/make_defs.mk
index a28ad0878..ff1d84b0d 100644
--- a/config/armv7a/make_defs.mk
+++ b/config/armv7a/make_defs.mk
@@ -76,17 +76,32 @@ GIT_LOG    := $(GIT) log --decorate
 #
 
 # --- Determine the C compiler and related flags ---
+ifeq ($(CC),)
 CC             := gcc
+CC_VENDOR      := gcc
+endif
+ifneq ($(CC_VENDOR),gcc)
+$(error gcc is required for this configuration.)
+endif
 # Enable IEEE Standard 1003.1-2004 (POSIX.1d). 
 # NOTE: This is needed to enable posix_memalign().
 CPPROCFLAGS    := -D_POSIX_C_SOURCE=200112L
-CMISCFLAGS     := -std=c99 -O3 -mfloat-abi=hard -mfpu=vfpv3 -marm -march=armv7-a #-g
+CMISCFLAGS     := -std=c99 -mfloat-abi=hard
 CPICFLAGS      := -fPIC
-CDBGFLAGS      := #-g
 CWARNFLAGS     := -Wall
-COPTFLAGS      := -marm -march=armv7-a -mfpu=vfpv3 -O3 -mfloat-abi=hard #-g
+
+ifneq ($(DEBUG_TYPE),off)
+CDBGFLAGS      := -g
+endif
+
+ifeq ($(DEBUG_TYPE),noopt)
+COPTFLAGS      := -O0
+else
+COPTFLAGS      := -O3
+endif
+
+CVECFLAGS      := -mfpu=vfpv3 -marm -march=armv7-a
 CKOPTFLAGS     := $(COPTFLAGS)
-CVECFLAGS      := #-msse3  # -mfpmath=sse
 
 # Aggregate all of the flags into multiple groups: one for standard
 # compilation, and one for each of the supported "special" compilation
diff --git a/config/armv8a/make_defs.mk b/config/armv8a/make_defs.mk
index 63c03c6a0..3cec43c92 100644
--- a/config/armv8a/make_defs.mk
+++ b/config/armv8a/make_defs.mk
@@ -76,18 +76,32 @@ GIT_LOG    := $(GIT) log --decorate
 #
 
 # --- Determine the C compiler and related flags ---
+ifeq ($(CC),)
 CC             := gcc
-
+CC_VENDOR      := gcc
+endif
+ifneq ($(CC_VENDOR),gcc)
+$(error gcc is required for this configuration.)
+endif
 # Enable IEEE Standard 1003.1-2004 (POSIX.1d). 
 # NOTE: This is needed to enable posix_memalign().
 CPPROCFLAGS    := -D_GNU_SOURCE
-CMISCFLAGS     := -std=c99 -march=armv8-a+fp+simd -ftree-vectorize -O3 -fopenmp -mcpu=cortex-a57.cortex-a53 -mtune=cortex-a57.cortex-a53
+CMISCFLAGS     := -std=c99 -fopenmp
 CPICFLAGS      := -fPIC
-CDBGFLAGS      := -g #-g3 -gdwarf-2 
 CWARNFLAGS     := -Wall
-COPTFLAGS      := -march=armv8-a+fp+simd -ftree-vectorize -O3 -mcpu=cortex-a57.cortex-a53 -mtune=cortex-a57.cortex-a53
+
+ifneq ($(DEBUG_TYPE),off)
+CDBGFLAGS      := -g
+endif
+
+ifeq ($(DEBUG_TYPE),noopt)
+COPTFLAGS      := -O0
+else
+COPTFLAGS      := -O3 -ftree-vectorize -mtune=cortex-a57.cortex-a53
+endif
+
+CVECFLAGS      := -march=armv8-a+fp+simd -mcpu=cortex-a57.cortex-a53
 CKOPTFLAGS     := $(COPTFLAGS)
-CVECFLAGS      := #-march=armv8-a+fp+simd -ftree-vectorize -O3 -mcpu=cortex-a57.cortex-a53 -mtune=cortex-a57.cortex-a53 #-march=armv8-a -O2 -mtune=cortex-a57 -mfpu=neon-fp-armv8 
 
 # Aggregate all of the flags into multiple groups: one for standard
 # compilation, and one for each of the supported "special" compilation
diff --git a/config/bulldozer/make_defs.mk b/config/bulldozer/make_defs.mk
index 13e306a02..772ac1c53 100644
--- a/config/bulldozer/make_defs.mk
+++ b/config/bulldozer/make_defs.mk
@@ -76,17 +76,32 @@ GIT_LOG    := $(GIT) log --decorate
 #
 
 # --- Determine the C compiler and related flags ---
+ifeq ($(CC),)
 CC             := gcc
+CC_VENDOR      := gcc
+endif
+ifneq ($(CC_VENDOR),gcc)
+$(error gcc is required for this configuration.)
+endif
 # Enable IEEE Standard 1003.1-2004 (POSIX.1d). 
 # NOTE: This is needed to enable posix_memalign().
 CPPROCFLAGS    := -D_POSIX_C_SOURCE=200112L
 CMISCFLAGS     := -std=c99 -fopenmp
 CPICFLAGS      := -fPIC
-CDBGFLAGS      := -g
 CWARNFLAGS     := -Wall
-COPTFLAGS      := -O0 -malign-double -funroll-all-loops
-CKOPTFLAGS     := $(COPTFLAGS)
+
+ifneq ($(DEBUG_TYPE),off)
+CDBGFLAGS      := -g
+endif
+
+ifeq ($(DEBUG_TYPE),noopt)
+COPTFLAGS      := -O0
+else
+COPTFLAGS      := -O2 -malign-double -funroll-all-loops
+endif
+
 CVECFLAGS      := -mavx -mfma -march=bdver2 -mfpmath=sse
+CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
 # compilation, and one for each of the supported "special" compilation
diff --git a/config/carrizo/make_defs.mk b/config/carrizo/make_defs.mk
index 5f5303ade..08a5baaaf 100644
--- a/config/carrizo/make_defs.mk
+++ b/config/carrizo/make_defs.mk
@@ -76,17 +76,32 @@ GIT_LOG    := $(GIT) log --decorate
 #
 
 # --- Determine the C compiler and related flags ---
+ifeq ($(CC),)
 CC             := gcc
+CC_VENDOR      := gcc
+endif
+ifneq ($(CC_VENDOR),gcc)
+$(error gcc is required for this configuration.)
+endif
 # Enable IEEE Standard 1003.1-2004 (POSIX.1d). 
 # NOTE: This is needed to enable posix_memalign().
 CPPROCFLAGS    := -D_POSIX_C_SOURCE=200112L
 CMISCFLAGS     := -std=c99 -fopenmp
 CPICFLAGS      := -fPIC
-CDBGFLAGS      := #-g
 CWARNFLAGS     := -Wall
-COPTFLAGS      := -O2 -mfpmath=sse -fomit-frame-pointer
+
+ifneq ($(DEBUG_TYPE),off)
+CDBGFLAGS      := -g
+endif
+
+ifeq ($(DEBUG_TYPE),noopt)
+COPTFLAGS      := -O0
+else
+COPTFLAGS      := -O2 -fomit-frame-pointer
+endif
+
+CVECFLAGS      := -mavx -mfma -march=native -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
-CVECFLAGS      := -mavx -mfma -march=native
 
 # Aggregate all of the flags into multiple groups: one for standard
 # compilation, and one for each of the supported "special" compilation
diff --git a/config/cortex-a15/make_defs.mk b/config/cortex-a15/make_defs.mk
index 078c063b7..e81c28f60 100644
--- a/config/cortex-a15/make_defs.mk
+++ b/config/cortex-a15/make_defs.mk
@@ -97,13 +97,10 @@ endif
 ifeq ($(DEBUG_TYPE),noopt)
 COPTFLAGS      := -O0
 else
-COPTFLAGS      := -march=armv7-a -mfpu=neon -O2
-endif
-
-ifneq ($(DEBUG_TYPE),noopt)
-CVECFLAGS      := #-msse3 -march=native # -mfpmath=sse
+COPTFLAGS      := -O2
 endif
 
+CVECFLAGS      := -march=armv7-a #-msse3 -march=native # -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/cortex-a9/make_defs.mk b/config/cortex-a9/make_defs.mk
index 7dbc0aa77..e81c28f60 100644
--- a/config/cortex-a9/make_defs.mk
+++ b/config/cortex-a9/make_defs.mk
@@ -97,13 +97,10 @@ endif
 ifeq ($(DEBUG_TYPE),noopt)
 COPTFLAGS      := -O0
 else
-COPTFLAGS      := -march=armv7-a -mfpu=neon -O2 -mfloat-abi=hard
-endif
-
-ifneq ($(DEBUG_TYPE),noopt)
-CVECFLAGS      := #-msse3 -march=native # -mfpmath=sse
+COPTFLAGS      := -O2
 endif
 
+CVECFLAGS      := -march=armv7-a #-msse3 -march=native # -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/dunnington/make_defs.mk b/config/dunnington/make_defs.mk
index d065640f5..4d06567d0 100644
--- a/config/dunnington/make_defs.mk
+++ b/config/dunnington/make_defs.mk
@@ -97,13 +97,10 @@ endif
 ifeq ($(DEBUG_TYPE),noopt)
 COPTFLAGS      := -O0
 else
-COPTFLAGS     := -O2 -mfpmath=sse -fomit-frame-pointer
-endif
-
-ifneq ($(DEBUG_TYPE),noopt)
-CVECFLAGS      := -msse3 -march=native
+COPTFLAGS      := -O2 -fomit-frame-pointer
 endif
 
+CVECFLAGS      := -msse3 -march=native -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/haswell/make_defs.mk b/config/haswell/make_defs.mk
index a1865a98b..895746fc5 100644
--- a/config/haswell/make_defs.mk
+++ b/config/haswell/make_defs.mk
@@ -97,13 +97,10 @@ endif
 ifeq ($(DEBUG_TYPE),noopt)
 COPTFLAGS      := -O0
 else
-COPTFLAGS      := -O3 -march=native
-endif
-
-ifneq ($(DEBUG_TYPE),noopt)
-CVECFLAGS      := -mavx2 -mfma -mfpmath=sse #-msse3 -march=native # -mfpmath=sse
+COPTFLAGS      := -O3
 endif
 
+CVECFLAGS      := -mavx2 -mfma -mfpmath=sse -march=native #-msse3 -march=native # -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/loongson3a/make_defs.mk b/config/loongson3a/make_defs.mk
index d3500a7c3..8296dcd92 100644
--- a/config/loongson3a/make_defs.mk
+++ b/config/loongson3a/make_defs.mk
@@ -97,13 +97,10 @@ endif
 ifeq ($(DEBUG_TYPE),noopt)
 COPTFLAGS      := -O0
 else
-COPTFLAGS      := -O3  -march=loongson3a -mtune=loongson3a
-endif
-
-ifneq ($(DEBUG_TYPE),noopt)
-CVECFLAGS      := #-msse3 -march=native # -mfpmath=sse
+COPTFLAGS      := -O3 -mtune=loongson3a
 endif
 
+CVECFLAGS      := -march=loongson3a #-msse3 -march=native # -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/mic/make_defs.mk b/config/mic/make_defs.mk
index 93e1efb9a..5e298269d 100644
--- a/config/mic/make_defs.mk
+++ b/config/mic/make_defs.mk
@@ -100,10 +100,7 @@ else
 COPTFLAGS      := -O3
 endif
 
-ifneq ($(DEBUG_TYPE),noopt)
 CVECFLAGS      := 
-endif
-
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/piledriver/make_defs.mk b/config/piledriver/make_defs.mk
index 89756bea1..08a5baaaf 100644
--- a/config/piledriver/make_defs.mk
+++ b/config/piledriver/make_defs.mk
@@ -97,13 +97,10 @@ endif
 ifeq ($(DEBUG_TYPE),noopt)
 COPTFLAGS      := -O0
 else
-COPTFLAGS      := -O2 -mfpmath=sse -fomit-frame-pointer
-endif
-
-ifneq ($(DEBUG_TYPE),noopt)
-CVECFLAGS      := -mavx -mfma -march=native
+COPTFLAGS      := -O2 -fomit-frame-pointer
 endif
 
+CVECFLAGS      := -mavx -mfma -march=native -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/power7/make_defs.mk b/config/power7/make_defs.mk
index 460f53d07..8beaa15fb 100644
--- a/config/power7/make_defs.mk
+++ b/config/power7/make_defs.mk
@@ -100,10 +100,7 @@ else
 COPTFLAGS      := -O3 -mtune=power7
 endif
 
-ifneq ($(DEBUG_TYPE),noopt)
 CVECFLAGS      := -mvsx
-endif
-
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/reference/make_defs.mk b/config/reference/make_defs.mk
index 509c4d9e5..b0ac0c62f 100644
--- a/config/reference/make_defs.mk
+++ b/config/reference/make_defs.mk
@@ -100,10 +100,7 @@ else
 COPTFLAGS      := -O2
 endif
 
-ifneq ($(DEBUG_TYPE),noopt)
 CVECFLAGS      := #-msse3 -march=native # -mfpmath=sse
-endif
-
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/sandybridge/make_defs.mk b/config/sandybridge/make_defs.mk
index c1fd57176..4b96d93f7 100644
--- a/config/sandybridge/make_defs.mk
+++ b/config/sandybridge/make_defs.mk
@@ -97,13 +97,10 @@ endif
 ifeq ($(DEBUG_TYPE),noopt)
 COPTFLAGS      := -O0
 else
-COPTFLAGS      := -O3 -march=native
-endif
-
-ifneq ($(DEBUG_TYPE),noopt)
-CVECFLAGS      := -mavx -mfpmath=sse #-msse3 -march=native # -mfpmath=sse
+COPTFLAGS      := -O3
 endif
 
+CVECFLAGS      := -mavx -mfpmath=sse -march=native #-msse3 -march=native # -mfpmath=sse
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/config/template/make_defs.mk b/config/template/make_defs.mk
index 509c4d9e5..b0ac0c62f 100644
--- a/config/template/make_defs.mk
+++ b/config/template/make_defs.mk
@@ -100,10 +100,7 @@ else
 COPTFLAGS      := -O2
 endif
 
-ifneq ($(DEBUG_TYPE),noopt)
 CVECFLAGS      := #-msse3 -march=native # -mfpmath=sse
-endif
-
 CKOPTFLAGS     := $(COPTFLAGS)
 
 # Aggregate all of the flags into multiple groups: one for standard
diff --git a/configure b/configure
index 4528a826e..63303434e 100755
--- a/configure
+++ b/configure
@@ -206,6 +206,7 @@ main()
 						;;
 					enable-debug)
 						debug_flag=1
+						debug_type=noopt
 						;;
 					enable-debug=*)
 						debug_flag=1
@@ -327,7 +328,7 @@ main()
 
 	# Check if the debug flag was specified.
 	if [ -n "${debug_flag}" ]; then
-		if [ ${debug_type} = 'opt' ]; then
+		if [ "x${debug_type}" = "xopt" ]; then
 			echo "${script_name}: enabling debug symbols with optimizations."
 		else
 			debug_type='noopt'