diff --git a/BLAS/SRC/icamax.f90 b/BLAS/SRC/icamax.f90
index a53cb1c4a..9be0d9fda 100644
--- a/BLAS/SRC/icamax.f90
+++ b/BLAS/SRC/icamax.f90
@@ -86,6 +86,9 @@ integer function icamax(n, x, incx)
    integer :: i, j, ix, jx
    real(wp) :: val, smax
    logical :: scaledsmax
+!  ..
+!  .. Intrinsic Functions ..
+   intrinsic :: abs, aimag, huge, real
 !
 !  Quick return if possible
 !
@@ -100,7 +103,7 @@ integer function icamax(n, x, incx)
    smax = -1
 !
 !  scaledsmax = .true. indicates that x(icamax) is finite but
-!  abs(real(x(icamax))) + abs(imag(x(icamax))) overflows
+!  abs(real(x(icamax))) + abs(aimag(x(icamax))) overflows
 !
    if (incx == 1) then
       ! code for increment equal to 1
@@ -109,7 +112,7 @@ integer function icamax(n, x, incx)
             ! return when first NaN found
             icamax = i
             return
-         elseif (abs(real(x(i))) > hugeval .or. abs(imag(x(i))) > hugeval) then
+         elseif (abs(real(x(i))) > hugeval .or. abs(aimag(x(i))) > hugeval) then
             ! keep looking for first NaN
             do j = i+1, n
                if (x(j) /= x(j)) then
@@ -123,18 +126,18 @@ integer function icamax(n, x, incx)
             return
          else ! still no Inf found yet
             if (.not. scaledsmax) then
-               ! no abs(real(x(i))) + abs(imag(x(i))) = Inf yet
-               val = abs(real(x(i))) + abs(imag(x(i)))
+               ! no abs(real(x(i))) + abs(aimag(x(i))) = Inf yet
+               val = abs(real(x(i))) + abs(aimag(x(i)))
                if (val > hugeval) then
                   scaledsmax = .true.
-                  smax = 0.25*abs(real(x(i))) + 0.25*abs(imag(x(i)))
+                  smax = 0.25*abs(real(x(i))) + 0.25*abs(aimag(x(i)))
                   icamax = i
                elseif (val > smax) then ! everything finite so far
                   smax = val
                   icamax = i
                endif
             else ! scaledsmax
-               val = 0.25*abs(real(x(i))) + 0.25*abs(imag(x(i)))
+               val = 0.25*abs(real(x(i))) + 0.25*abs(aimag(x(i)))
                if (val > smax) then
                   smax = val
                   icamax = i
@@ -150,7 +153,7 @@ integer function icamax(n, x, incx)
             ! return when first NaN found
             icamax = i
             return
-         elseif (abs(real(x(ix))) > hugeval .or. abs(imag(x(ix))) > hugeval) then
+         elseif (abs(real(x(ix))) > hugeval .or. abs(aimag(x(ix))) > hugeval) then
             ! keep looking for first NaN
             jx = ix + incx
             do j = i+1, n
@@ -166,18 +169,18 @@ integer function icamax(n, x, incx)
             return
          else ! still no Inf found yet
             if (.not. scaledsmax) then
-               ! no abs(real(x(ix))) + abs(imag(x(ix))) = Inf yet
-               val = abs(real(x(ix))) + abs(imag(x(ix)))
+               ! no abs(real(x(ix))) + abs(aimag(x(ix))) = Inf yet
+               val = abs(real(x(ix))) + abs(aimag(x(ix)))
                if (val > hugeval) then
                   scaledsmax = .true.
-                  smax = 0.25*abs(real(x(ix))) + 0.25*abs(imag(x(ix)))
+                  smax = 0.25*abs(real(x(ix))) + 0.25*abs(aimag(x(ix)))
                   icamax = i
                elseif (val > smax) then ! everything finite so far
                   smax = val
                   icamax = i
                endif
             else ! scaledsmax
-               val = 0.25*abs(real(x(ix))) + 0.25*abs(imag(x(ix)))
+               val = 0.25*abs(real(x(ix))) + 0.25*abs(aimag(x(ix)))
                if (val > smax) then
                   smax = val
                   icamax = i
diff --git a/BLAS/SRC/izamax.f90 b/BLAS/SRC/izamax.f90
index 02d97dcf9..35b81d741 100644
--- a/BLAS/SRC/izamax.f90
+++ b/BLAS/SRC/izamax.f90
@@ -86,6 +86,9 @@ integer function izamax(n, x, incx)
    integer :: i, j, ix, jx
    real(wp) :: val, smax
    logical :: scaledsmax
+!  ..
+!  .. Intrinsic Functions ..
+   intrinsic :: abs, dimag, huge, real
 !
 !  Quick return if possible
 !
@@ -100,7 +103,7 @@ integer function izamax(n, x, incx)
    smax = -1
 !
 !  scaledsmax = .true. indicates that x(izamax) is finite but
-!  abs(real(x(izamax))) + abs(imag(x(izamax))) overflows
+!  abs(real(x(izamax))) + abs(dimag(x(izamax))) overflows
 !
    if (incx == 1) then
       ! code for increment equal to 1
@@ -109,7 +112,7 @@ integer function izamax(n, x, incx)
             ! return when first NaN found
             izamax = i
             return
-         elseif (abs(real(x(i))) > hugeval .or. abs(imag(x(i))) > hugeval) then
+         elseif (abs(real(x(i))) > hugeval .or. abs(dimag(x(i))) > hugeval) then
             ! keep looking for first NaN
             do j = i+1, n
                if (x(j) /= x(j)) then
@@ -123,18 +126,18 @@ integer function izamax(n, x, incx)
             return
          else ! still no Inf found yet
             if (.not. scaledsmax) then
-               ! no abs(real(x(i))) + abs(imag(x(i))) = Inf yet
-               val = abs(real(x(i))) + abs(imag(x(i)))
+               ! no abs(real(x(i))) + abs(dimag(x(i))) = Inf yet
+               val = abs(real(x(i))) + abs(dimag(x(i)))
                if (val > hugeval) then
                   scaledsmax = .true.
-                  smax = 0.25*abs(real(x(i))) + 0.25*abs(imag(x(i)))
+                  smax = 0.25*abs(real(x(i))) + 0.25*abs(dimag(x(i)))
                   izamax = i
                elseif (val > smax) then ! everything finite so far
                   smax = val
                   izamax = i
                endif
             else ! scaledsmax
-               val = 0.25*abs(real(x(i))) + 0.25*abs(imag(x(i)))
+               val = 0.25*abs(real(x(i))) + 0.25*abs(dimag(x(i)))
                if (val > smax) then
                   smax = val
                   izamax = i
@@ -150,7 +153,7 @@ integer function izamax(n, x, incx)
             ! return when first NaN found
             izamax = i
             return
-         elseif (abs(real(x(ix))) > hugeval .or. abs(imag(x(ix))) > hugeval) then
+         elseif (abs(real(x(ix))) > hugeval .or. abs(dimag(x(ix))) > hugeval) then
             ! keep looking for first NaN
             jx = ix + incx
             do j = i+1, n
@@ -166,18 +169,18 @@ integer function izamax(n, x, incx)
             return
          else ! still no Inf found yet
             if (.not. scaledsmax) then
-               ! no abs(real(x(ix))) + abs(imag(x(ix))) = Inf yet
-               val = abs(real(x(ix))) + abs(imag(x(ix)))
+               ! no abs(real(x(ix))) + abs(dimag(x(ix))) = Inf yet
+               val = abs(real(x(ix))) + abs(dimag(x(ix)))
                if (val > hugeval) then
                   scaledsmax = .true.
-                  smax = 0.25*abs(real(x(ix))) + 0.25*abs(imag(x(ix)))
+                  smax = 0.25*abs(real(x(ix))) + 0.25*abs(dimag(x(ix)))
                   izamax = i
                elseif (val > smax) then ! everything finite so far
                   smax = val
                   izamax = i
                endif
             else ! scaledsmax
-               val = 0.25*abs(real(x(ix))) + 0.25*abs(imag(x(ix)))
+               val = 0.25*abs(real(x(ix))) + 0.25*abs(dimag(x(ix)))
                if (val > smax) then
                   smax = val
                   izamax = i
diff --git a/BLAS/TESTING/CMakeLists.txt b/BLAS/TESTING/CMakeLists.txt
index ae82cf937..597e81738 100644
--- a/BLAS/TESTING/CMakeLists.txt
+++ b/BLAS/TESTING/CMakeLists.txt
@@ -15,6 +15,12 @@ macro(add_blas_test name src)
       -DINTDIR=${CMAKE_CFG_INTDIR}
       -P "${LAPACK_SOURCE_DIR}/TESTING/runtest.cmake")
   endif()
+
+  # Disable constant propagation for NAG compiler to avoid issues with
+  # special values (Inf, NaN) returned by SXVALS and DXVALS.
+  if(CMAKE_Fortran_COMPILER_ID STREQUAL "NAG")
+    target_compile_options(${name} PRIVATE "-Onopropagate")
+  endif()
 endmacro()
 
 if(BUILD_SINGLE)
diff --git a/CBLAS/testing/c_dblat3.f b/CBLAS/testing/c_dblat3.f
index 7d7c8e721..9d8f0bb81 100644
--- a/CBLAS/testing/c_dblat3.f
+++ b/CBLAS/testing/c_dblat3.f
@@ -2821,13 +2821,13 @@ SUBROUTINE DCHK6( SNAME, EPS, THRESH, NOUT, NTRA, TRACE, REWI,
      $ ' (', I6, ' CALL', 'S)' )
  9998 FORMAT( ' ******* FATAL ERROR - PARAMETER NUMBER ', I2, ' WAS CH',
      $      'ANGED INCORRECTLY *******' )
- 9997 FORMAT( ' ', A13, ' COMPLETED THE COMPUTATIONAL TESTS (', I6, ' C',
-     $      'ALLS)', /' ******* BUT WITH MAXIMUM TEST RATIO', F8.2,
-     $      ' - SUSPECT *******' )
+ 9997 FORMAT( ' ', A13, ' COMPLETED THE COMPUTATIONAL TESTS (', I6,
+     $      ' C', 'ALLS)', /' ******* BUT WITH MAXIMUM TEST RATIO',
+     $      F8.2, ' - SUSPECT *******' )
  9996 FORMAT( ' ******* ', A13, ' FAILED ON CALL NUMBER:' )
- 9995 FORMAT( 1X, I6, ': ', A13, '(''',A1, ''',''',A1, ''',''', A1,''',',
-     $      2( I3, ',' ), F4.1, ', A,', I3, ', B,', I3, ',', F4.1, ', ',
-     $      'C,', I3, ').' )
+ 9995 FORMAT( 1X, I6, ': ', A13, '(''',A1, ''',''',A1, ''',''', A1,
+     $      ''',', 2( I3, ',' ), F4.1, ', A,', I3, ', B,', I3, ',',
+     $      F4.1, ', ', 'C,', I3, ').' )
  9994 FORMAT( ' ******* FATAL ERROR - ERROR-EXIT TAKEN ON VALID CALL *',
      $      '******' )
 *
diff --git a/CBLAS/testing/c_sblat3.f b/CBLAS/testing/c_sblat3.f
index 15a5c1d05..f9277655a 100644
--- a/CBLAS/testing/c_sblat3.f
+++ b/CBLAS/testing/c_sblat3.f
@@ -2822,13 +2822,13 @@ SUBROUTINE SCHK6( SNAME, EPS, THRESH, NOUT, NTRA, TRACE, REWI,
      $ ' (', I6, ' CALL', 'S)' )
  9998 FORMAT( ' ******* FATAL ERROR - PARAMETER NUMBER ', I2, ' WAS CH',
      $      'ANGED INCORRECTLY *******' )
- 9997 FORMAT( ' ', A13, ' COMPLETED THE COMPUTATIONAL TESTS (', I6, ' C',
-     $      'ALLS)', /' ******* BUT WITH MAXIMUM TEST RATIO', F8.2,
-     $      ' - SUSPECT *******' )
+ 9997 FORMAT( ' ', A13, ' COMPLETED THE COMPUTATIONAL TESTS (', I6,
+     $      ' C', 'ALLS)', /' ******* BUT WITH MAXIMUM TEST RATIO',
+     $      F8.2, ' - SUSPECT *******' )
  9996 FORMAT( ' ******* ', A13, ' FAILED ON CALL NUMBER:' )
- 9995 FORMAT( 1X, I6, ': ', A13, '(''',A1, ''',''',A1, ''',''', A1,''',',
-     $      2( I3, ',' ), F4.1, ', A,', I3, ', B,', I3, ',', F4.1, ', ',
-     $      'C,', I3, ').' )
+ 9995 FORMAT( 1X, I6, ': ', A13, '(''',A1, ''',''',A1, ''',''', A1,
+     $      ''',', 2( I3, ',' ), F4.1, ', A,', I3, ', B,', I3, ',',
+     $      F4.1, ', ', 'C,', I3, ').' )
  9994 FORMAT( ' ******* FATAL ERROR - ERROR-EXIT TAKEN ON VALID CALL *',
      $      '******' )
 *