From: Tom de Vries <tdevries@suse.de>
Date: Wed, 26 Jan 2022 13:16:42 +0000 (+0100)
Subject: [nvptx] Update bar.sync for ptx isa 6.0
X-Git-Tag: basepoints/gcc-13~1345
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=57f971f99209cc950d7e706b7b52f4c9ef1d10b0;p=thirdparty%2Fgcc.git

[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 --git a/gcc/config/nvptx/nvptx-opts.h b/gcc/config/nvptx/nvptx-opts.h
index daae72ff70e0..c754a5193ce3 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 9fda2f0d86c0..065d7aa210c8 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 9cbbd956f9d5..b39116520ba1 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")])