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.
---
Changes from v1:
- Original standalone submission:
<https://inbox.sourceware.org/gcc-patches/alpine.deb.2.21.2412300410050.20...@angie.orcam.me.uk/>.
- Fold into this series to prevent failures with newly-added tests in 2/7,
6/7, and 7/7.
- Mention the likely cause of the regression in the description.
---
gcc/config/alpha/alpha.cc | 5 +++--
gcc/testsuite/gcc.target/alpha/target-bwx-1.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-bwx-2.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-bwx-3.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-bwx-4.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-cix-1.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-cix-2.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-cix-3.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-cix-4.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-fix-1.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-fix-2.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-fix-3.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-fix-4.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-max-1.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-max-2.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-max-3.c | 6 ++++++
gcc/testsuite/gcc.target/alpha/target-max-4.c | 6 ++++++
17 files changed, 99 insertions(+), 2 deletions(-)
gcc-alpha-flags-explicit.diff
Index: gcc/gcc/config/alpha/alpha.cc
===================================================================
--- gcc.orig/gcc/config/alpha/alpha.cc
+++ gcc/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)
Index: gcc/gcc/testsuite/gcc.target/alpha/target-bwx-1.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-bwx-2.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-bwx-3.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-bwx-4.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-cix-1.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-cix-2.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-cix-3.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-cix-4.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-fix-1.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-fix-2.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-fix-3.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-fix-4.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-max-1.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-max-2.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-max-3.c
===================================================================
--- /dev/null
+++ gcc/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
Index: gcc/gcc/testsuite/gcc.target/alpha/target-max-4.c
===================================================================
--- /dev/null
+++ gcc/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
