Alpha: Always respect -mbwx, -mcix, -mfix, -mmax, and their inverse

Contrary to user documentation the `-mbwx', `-mcix', `-mfix', `-mmax'
feature options and their inverse forms are ignored whenever `-mcpu='
option is in effect, either by having been given explicitly or where
configured as the default such as with the `alphaev56-linux-gnu' target.
In the latter case there is no way to change the settings these options
are supposed to tweak other than with `-mcpu=' and the settings cannot
be individually controlled, making all the feature options permanently
inactive.

It seems a regression from commit 7816bea0e23b ("config.gcc: Reorganize
--with-cpu logic.") back in 2003, which replaced the setting of the
default feature mask with the setting of the default CPU across a few
targets, and the complementing logic in the Alpha backend wasn't updated
accordingly.

Fix this by making the individual feature options take precedence over
`-mcpu='.  Add test cases to verify this is the case, and to cover the
defaults as well for the boundary cases.

This has a drawback where the order of the options is ignored between
`-mcpu=' and these individual options, so e.g. `-mno-bwx -mcpu=ev6' will
keep the BWX feature disabled even though `-mcpu=ev6' comes later in the
command line.  This may affect some scenarios involving user overrides
such as with CFLAGS passed to `configure' and `make' invocations.  I do
believe it has been our practice anyway for more finegrained options to
override group options regardless of their relative order on the command
line and in any case using `-mcpu=ev6 -mbwx' as the override will do the
right thing if required, canceling any previous `-mno-bwx'.

This has been spotted with `alphaev56-linux-gnu' target verification and
a recently added test case:

FAIL: gcc.target/alpha/stwx0.c   -O1   scan-assembler-times \\sldq_u\\s 2
FAIL: gcc.target/alpha/stwx0.c   -O1   scan-assembler-times \\smskwh\\s 1
FAIL: gcc.target/alpha/stwx0.c   -O1   scan-assembler-times \\smskwl\\s 1
FAIL: gcc.target/alpha/stwx0.c   -O1   scan-assembler-times \\sstq_u\\s 2

(and similarly for the remaining optimization levels covered) which this
fix has addressed.

	gcc/
	* config/alpha/alpha.cc (alpha_option_override): Ignore CPU
	flags corresponding to features the enabling or disabling of
	which has been requested with an individual feature option.

	gcc/testsuite/
	* gcc.target/alpha/target-bwx-1.c: New file.
	* gcc.target/alpha/target-bwx-2.c: New file.
	* gcc.target/alpha/target-bwx-3.c: New file.
	* gcc.target/alpha/target-bwx-4.c: New file.
	* gcc.target/alpha/target-cix-1.c: New file.
	* gcc.target/alpha/target-cix-2.c: New file.
	* gcc.target/alpha/target-cix-3.c: New file.
	* gcc.target/alpha/target-cix-4.c: New file.
	* gcc.target/alpha/target-fix-1.c: New file.
	* gcc.target/alpha/target-fix-2.c: New file.
	* gcc.target/alpha/target-fix-3.c: New file.
	* gcc.target/alpha/target-fix-4.c: New file.
	* gcc.target/alpha/target-max-1.c: New file.
	* gcc.target/alpha/target-max-2.c: New file.
	* gcc.target/alpha/target-max-3.c: New file.
	* gcc.target/alpha/target-max-4.c: New file.

17 files changed, 99 insertions, 2 deletions

diff --git a/gcc/config/alpha/alpha.cc b/gcc/config/alpha/alpha.cc
index 030dc77..958a785 100644
--- a/gcc/config/alpha/alpha.cc
+++ b/gcc/config/alpha/alpha.cc
@@ -460,8 +460,9 @@ alpha_option_override (void)
 	    line_size = cpu_table[i].line_size;
 	    l1_size = cpu_table[i].l1_size;
 	    l2_size = cpu_table[i].l2_size;
-	    target_flags &= ~ (MASK_BWX | MASK_MAX | MASK_FIX | MASK_CIX);
-	    target_flags |= cpu_table[i].flags;
+	    target_flags &= ~((MASK_BWX | MASK_MAX | MASK_FIX | MASK_CIX)
+			      & ~target_flags_explicit);
+	    target_flags |= cpu_table[i].flags & ~target_flags_explicit;
 	    break;
 	  }
       if (i == ct_size)
diff --git a/gcc/testsuite/gcc.target/alpha/target-bwx-1.c b/gcc/testsuite/gcc.target/alpha/target-bwx-1.c
new file mode 100644
index 0000000..fcb38aa
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-bwx-1.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev5" } */
+
+#ifdef __alpha_bwx__
+# error "BWX enabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-bwx-2.c b/gcc/testsuite/gcc.target/alpha/target-bwx-2.c
new file mode 100644
index 0000000..119f32b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-bwx-2.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev56" } */
+
+#ifndef __alpha_bwx__
+# error "BWX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-bwx-3.c b/gcc/testsuite/gcc.target/alpha/target-bwx-3.c
new file mode 100644
index 0000000..7f2db60
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-bwx-3.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev5 -mbwx" } */
+
+#ifndef __alpha_bwx__
+# error "BWX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-bwx-4.c b/gcc/testsuite/gcc.target/alpha/target-bwx-4.c
new file mode 100644
index 0000000..5b41fcf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-bwx-4.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev56 -mno-bwx" } */
+
+#ifdef __alpha_bwx__
+# error "BWX enabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-cix-1.c b/gcc/testsuite/gcc.target/alpha/target-cix-1.c
new file mode 100644
index 0000000..19edd24
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-cix-1.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev6" } */
+
+#ifdef __alpha_cix__
+# error "CIX enabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-cix-2.c b/gcc/testsuite/gcc.target/alpha/target-cix-2.c
new file mode 100644
index 0000000..e433e23
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-cix-2.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev67" } */
+
+#ifndef __alpha_cix__
+# error "CIX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-cix-3.c b/gcc/testsuite/gcc.target/alpha/target-cix-3.c
new file mode 100644
index 0000000..b4fd3d4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-cix-3.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev6 -mcix" } */
+
+#ifndef __alpha_cix__
+# error "CIX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-cix-4.c b/gcc/testsuite/gcc.target/alpha/target-cix-4.c
new file mode 100644
index 0000000..85ebeb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-cix-4.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev67 -mno-cix" } */
+
+#ifdef __alpha_cix__
+# error "CIX enabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-fix-1.c b/gcc/testsuite/gcc.target/alpha/target-fix-1.c
new file mode 100644
index 0000000..f9515c3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-fix-1.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=pca56" } */
+
+#ifdef __alpha_fix__
+# error "FIX enabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-fix-2.c b/gcc/testsuite/gcc.target/alpha/target-fix-2.c
new file mode 100644
index 0000000..7b12ce8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-fix-2.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev6" } */
+
+#ifndef __alpha_fix__
+# error "FIX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-fix-3.c b/gcc/testsuite/gcc.target/alpha/target-fix-3.c
new file mode 100644
index 0000000..1e98ce0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-fix-3.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=pca56 -mfix" } */
+
+#ifndef __alpha_fix__
+# error "FIX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-fix-4.c b/gcc/testsuite/gcc.target/alpha/target-fix-4.c
new file mode 100644
index 0000000..34a4448
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-fix-4.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev6 -mno-fix" } */
+
+#ifdef __alpha_fix__
+# error "FIX enabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-max-1.c b/gcc/testsuite/gcc.target/alpha/target-max-1.c
new file mode 100644
index 0000000..3fd5fbf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-max-1.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev56" } */
+
+#ifdef __alpha_max__
+# error "MAX enabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-max-2.c b/gcc/testsuite/gcc.target/alpha/target-max-2.c
new file mode 100644
index 0000000..e6caec2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-max-2.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=pca56" } */
+
+#ifndef __alpha_max__
+# error "MAX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-max-3.c b/gcc/testsuite/gcc.target/alpha/target-max-3.c
new file mode 100644
index 0000000..c0e0d1b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-max-3.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=ev56 -mmax" } */
+
+#ifndef __alpha_max__
+# error "MAX disabled"
+#endif
diff --git a/gcc/testsuite/gcc.target/alpha/target-max-4.c b/gcc/testsuite/gcc.target/alpha/target-max-4.c
new file mode 100644
index 0000000..b1599b7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/target-max-4.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-mcpu=pca56 -mno-max" } */
+
+#ifdef __alpha_max__
+# error "MAX enabled"
+#endif