[gcc r12-7891] [nvptx] Add march-map

[gcc r12-7891] [nvptx] Add march-map

[Tom de Vries]

https://gcc.gnu.org/g:de0ef04419e90eacf0d1ddb265552a1b08c18d4b

commit r12-7891-gde0ef04419e90eacf0d1ddb265552a1b08c18d4b
Author: Tom de Vries <tdevries@suse.de>
Date:   Tue Mar 29 10:32:13 2022 +0200

    [nvptx] Add march-map
    
    Say we have an sm_50 board, and we want to run a benchmark using the highest
    possible march setting.
    
    Currently there's march=sm_30, march=sm_35, march=sm_53, but no march=sm_50.
    
    So, we'd need to pick march=sm_35.
    
    Likewise, for a test script that handles multiple boards, we'd need a mapping
    from native board sm_xx to march, which might have to be updated with newer
    gcc releases.
    
    Add an option march-map, such that we can just specify march-map=sm_50, and
    let the compiler map this to the appropriate march.
    
    The option is implemented as a list of aliases, such that we have a somewhat
    lengthy (17 lines in total):
    ...
    $ gcc --help=target
      ...
      -march-map=sm_30            Same as -misa=sm_30.
      -march-map=sm_32            Same as -misa=sm_30.
      ...
      -march-map=sm_87            Same as -misa=sm_80.
      -march-map=sm_90            Same as -misa=sm_80.
    ...
    
    This implementation was chosen in the hope that it'll be easier if
    we end up with some misa multilib.
    
    It would be nice to have the mapping list generated from an updated
    nvptx-sm.def, but for now it's spelled out in nvptx.opt.
    
    Tested on nvptx.
    
    gcc/ChangeLog:
    
    2022-03-29  Tom de Vries  <tdevries@suse.de>
    
            PR target/104714
            * config/nvptx/nvptx.opt (march-map=*): Add aliases.
    
    gcc/testsuite/ChangeLog:
    
    2022-03-29  Tom de Vries  <tdevries@suse.de>
    
            PR target/104714
            * gcc.target/nvptx/march-map.c: New test.

Diff:
---
 gcc/config/nvptx/nvptx.opt                 | 51 ++++++++++++++++++++++++++++++
 gcc/testsuite/gcc.target/nvptx/march-map.c |  5 +++
 2 files changed, 56 insertions(+)

diff --git a/gcc/config/nvptx/nvptx.opt b/gcc/config/nvptx/nvptx.opt
index b5d0170e9e9..58eddeeabf4 100644
--- a/gcc/config/nvptx/nvptx.opt
+++ b/gcc/config/nvptx/nvptx.opt
@@ -60,6 +60,57 @@ march=
 Target RejectNegative Joined Alias(misa=)
 Alias:
 
+march-map=sm_30
+Target RejectNegative Alias(misa=,sm_30)
+
+march-map=sm_32
+Target RejectNegative Alias(misa=,sm_30)
+
+march-map=sm_35
+Target RejectNegative Alias(misa=,sm_35)
+
+march-map=sm_37
+Target RejectNegative Alias(misa=,sm_35)
+
+march-map=sm_50
+Target RejectNegative Alias(misa=,sm_35)
+
+march-map=sm_52
+Target RejectNegative Alias(misa=,sm_35)
+
+march-map=sm_53
+Target RejectNegative Alias(misa=,sm_53)
+
+march-map=sm_60
+Target RejectNegative Alias(misa=,sm_53)
+
+march-map=sm_61
+Target RejectNegative Alias(misa=,sm_53)
+
+march-map=sm_62
+Target RejectNegative Alias(misa=,sm_53)
+
+march-map=sm_70
+Target RejectNegative Alias(misa=,sm_70)
+
+march-map=sm_72
+Target RejectNegative Alias(misa=,sm_70)
+
+march-map=sm_75
+Target RejectNegative Alias(misa=,sm_75)
+
+march-map=sm_80
+Target RejectNegative Alias(misa=,sm_80)
+
+march-map=sm_86
+Target RejectNegative Alias(misa=,sm_80)
+
+march-map=sm_87
+Target RejectNegative Alias(misa=,sm_80)
+
+march-map=sm_90
+Target RejectNegative Alias(misa=,sm_80)
+
 Enum
 Name(ptx_version) Type(int)
 Known PTX ISA versions (for use with the -mptx= option):
diff --git a/gcc/testsuite/gcc.target/nvptx/march-map.c b/gcc/testsuite/gcc.target/nvptx/march-map.c
new file mode 100644
index 00000000000..00838e55fc0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/nvptx/march-map.c
@@ -0,0 +1,5 @@
+/* { dg-options "-march-map=sm_50" } */
+
+#include "main.c"
+
+/* { dg-final { scan-assembler-times "\\.target\tsm_35" 1 } } */