testsuite: Add support for scanning assembly with comparitor

There is currently no support for matching at least x lines of assembly
(only scan-assembler-times). This patch would allow setting upper or lower
bounds.

Use case: using different scheduler descriptions and/or cost models will change
assembler output. Testing common functionality across tunes would require a
separate testcase per tune since each assembly output would be different. If we
know a base number of lines should appear across all tunes (i.e. testing return
values: we expect at minimum n stores into register x), we can lower-bound the
test to search for scan-assembler-bound {RE for storing into register x} >= n.
This avoids artificially inflating the scan-assembler-times expected count due
to the assembler choosing to perform extra stores into register x (using it as
a temporary register).

The testcase would be more robust to cpu/tune changes at the cost of not being
as granular towards specific cpu tuning.

gcc/ChangeLog:

	* doc/sourcebuild.texi: add scan-assembler-bound

gcc/testsuite/ChangeLog:

	* lib/scanasm.exp: add scan-assembler-bound

Signed-off-by: Edwin Lu <ewlu@rivosinc.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index c431956..7b747bfa 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -3403,6 +3403,10 @@ excluding LTO sections.
 Passes if @var{regex} is matched exactly @var{num} times in the test's
 assembler output, excluding LTO sections.
 
+@item scan-assembler-bound @var{regex} @var{cmp} @var{num} [@{ target/xfail @var{selector} @}]
+Passes if @var{regex} is matched @var{cmp} @var{num} times in the test's
+assembler output, excluding LTO sections. @var{cmp} is a comparitor.
+
 @item scan-assembler-dem @var{regex} [@{ target/xfail @var{selector} @}]
 Passes if @var{regex} matches text in the test's demangled assembler output,
 excluding LTO sections.