Reset -mpower8-fusion for power9 inlining power8 functions, PR 102059.
This patch is an attempt to make a much simpler patch to fix PR target/102059
than the previous patch.
It just fixes the issue that if a function is specifically declared as a power8
function, you can't inline in functions that are specified with power9 or
power10 options.
The issue is -mpower8-fusion is cleared when you use -mcpu=power9 or
-mcpu=power10. When I wrote the code for controlling which function can inline
other functions, -mpower8-fusion was set for -mcpu=power9 (-mcpu=power10 was
not an option at that time). This patch fixes this particular problem.
Perhaps -mpower8-fusion should go away in the GCC 13 time frame. This patch
just goes in and resets the fusion bit for testing inlines.
I have built a bootstrapped little endian compiler on power9 and the tests had
no regressions.
I have built a bootstrapped big endian compiler on power8 and I tested both
32-bit and 64-bit builds, and there were no regressions.
Can I install this into the trunk and back port it into GCC 11 after a burn-in
period?
2022-02-08 Michael Meissner <meiss...@linux.ibm.com>
gcc/
PR target/102059
* config/rs6000/rs6000.cc (rs6000_can_inline_p): Don't test for
power8-fusion if the caller was power9 or power10.
gcc/testsuite/
PR target/102059
* gcc.target/powerpc/pr102059-4.c: New test.
---
gcc/config/rs6000/rs6000.cc | 8 ++++++++
gcc/testsuite/gcc.target/powerpc/pr102059-4.c | 20 +++++++++++++++++++
2 files changed, 28 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/powerpc/pr102059-4.c
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index eaba9a2d698..e2d94421ae9 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -25278,6 +25278,14 @@ rs6000_can_inline_p (tree caller, tree callee)
callee_isa &= ~OPTION_MASK_HTM;
explicit_isa &= ~OPTION_MASK_HTM;
}
+
+ /* Power9 and power10 do not set power8-fusion. If the callee was
+ explicitly compiled for power8, and the caller was power9 or
+ power10, ignore the power8-fusion bits if it was set by
+ default. */
+ if ((caller_isa & OPTION_MASK_P8_FUSION) == 0
+ && (explicit_isa & OPTION_MASK_P8_FUSION) == 0)
+ callee_isa &= ~OPTION_MASK_P8_FUSION;
}
/* The callee's options must be a subset of the caller's options, i.e.
diff --git a/gcc/testsuite/gcc.target/powerpc/pr102059-4.c
b/gcc/testsuite/gcc.target/powerpc/pr102059-4.c
new file mode 100644
index 00000000000..627c6f820c7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr102059-4.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdejagnu-cpu=power10 -Wno-attributes" } */
+
+/* Verify that power10 can explicity include functions compiled for power8.
+ The issue is -mcpu=power8 enables -mpower8-fusion, but -mcpu=power9 or
+ -mcpu=power10 do not set power8-fusion by default. */
+
+static inline int __attribute__ ((always_inline,target("cpu=power8")))
+foo (int *b)
+{
+ *b += 10;
+ return *b;
+}
+
+int
+bar (int *a)
+{
+ *a = foo (a);
+ return 0;
+}
--
2.34.1
--
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meiss...@linux.ibm.com
