[gcc r12-6968] [nvptx] Update bar.sync for ptx isa 6.0

[Tom de Vries]

https://gcc.gnu.org/g:57f971f99209cc950d7e706b7b52f4c9ef1d10b0

commit r12-6968-g57f971f99209cc950d7e706b7b52f4c9ef1d10b0
Author: Tom de Vries <tdevries@suse.de>
Date:   Wed Jan 26 14:16:42 2022 +0100

    [nvptx] Update bar.sync for ptx isa 6.0
    
    In ptx isa 6.0, a new barrier instruction was added, and bar.sync was
    redefined as barrier.sync.aligned.
    
    The aligned modifier indicates that all threads in a CTA will execute the same
    barrier instruction.
    
    The seems fine for a form "bar.sync 0".
    
    But a "bar.sync %rx,64" (as used for vector length > 32) may execute a
    diffferent barrier depending on the value of %rx, so we can't assume it's
    aligned.
    
    Fix this by using "barrier.sync %rx,64" instead.
    
    Tested on x86_64 with nvptx accelerator.
    
    gcc/ChangeLog:
    
    2022-01-27  Tom de Vries  <tdevries@suse.de>
    
            * config/nvptx/nvptx-opts.h (enum ptx_version): Add PTX_VERSION_6_0.
            * config/nvptx/nvptx.h (TARGET_PTX_6_0): New macro.
            * config/nvptx/nvptx.md (define_insn "nvptx_barsync"): Use barrier
            insn for TARGET_PTX_6_0.

Diff:
---
 gcc/config/nvptx/nvptx-opts.h | 1 +
 gcc/config/nvptx/nvptx.h      | 1 +
 gcc/config/nvptx/nvptx.md     | 8 ++++++--
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/gcc/config/nvptx/nvptx-opts.h b/gcc/config/nvptx/nvptx-opts.h
index daae72ff70e..c754a5193ce 100644
--- a/gcc/config/nvptx/nvptx-opts.h
+++ b/gcc/config/nvptx/nvptx-opts.h
@@ -32,6 +32,7 @@ enum ptx_isa
 enum ptx_version
 {
   PTX_VERSION_3_1,
+  PTX_VERSION_6_0,
   PTX_VERSION_6_3,
   PTX_VERSION_7_0
 };
diff --git a/gcc/config/nvptx/nvptx.h b/gcc/config/nvptx/nvptx.h
index 9fda2f0d86c..065d7aa210c 100644
--- a/gcc/config/nvptx/nvptx.h
+++ b/gcc/config/nvptx/nvptx.h
@@ -91,6 +91,7 @@
 #define TARGET_SM75 (ptx_isa_option >= PTX_ISA_SM75)
 #define TARGET_SM80 (ptx_isa_option >= PTX_ISA_SM80)
 
+#define TARGET_PTX_6_0 (ptx_version_option >= PTX_VERSION_6_0)
 #define TARGET_PTX_6_3 (ptx_version_option >= PTX_VERSION_6_3)
 #define TARGET_PTX_7_0 (ptx_version_option >= PTX_VERSION_7_0)
 
diff --git a/gcc/config/nvptx/nvptx.md b/gcc/config/nvptx/nvptx.md
index 9cbbd956f9d..b39116520ba 100644
--- a/gcc/config/nvptx/nvptx.md
+++ b/gcc/config/nvptx/nvptx.md
@@ -1968,9 +1968,13 @@
   ""
   {
     if (INTVAL (operands[1]) == 0)
-      return "\\tbar.sync\\t%0;";
+      return (TARGET_PTX_6_0
+	      ? "\\tbarrier.sync.aligned\\t%0;"
+	      : "\\tbar.sync\\t%0;");
     else
-      return "\\tbar.sync\\t%0, %1;";
+      return (TARGET_PTX_6_0
+	      ? "\\tbarrier.sync\\t%0, %1;"
+	      : "\\tbar.sync\\t%0, %1;");
   }
   [(set_attr "predicable" "false")])