From: Alexander Monakov <amonakov@ispras.ru>
Date: Tue, 2 Feb 2016 18:24:25 +0000 (+0300)
Subject: nvptx: do not use alternative spelling of unsigned comparisons
X-Git-Tag: basepoints/gcc-7~1151
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=578fb2259b0f644142f9a795a3fc433cba5f2da6;p=thirdparty%2Fgcc.git

nvptx: do not use alternative spelling of unsigned comparisons

gcc/ChangeLog:
	* config/nvptx/nvptx.c (nvptx_print_operand): Treat LEU, GEU, LTU, GTU
        like LE, GE, LT, GT when emitting relational operator.

gcc/testsuite/ChangeLog:
	* gcc.target/nvptx/unsigned-cmp.c: New test.

From-SVN: r233088
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0e72ed1d0585..e8338107f18c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2016-02-02  Alexander Monakov  <amonakov@ispras.ru>
+
+	* config/nvptx/nvptx.c (nvptx_print_operand): Treat LEU, GEU, LTU, GTU
+	like LE, GE, LT, GT when emitting relational operator.
+
 2016-02-02  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* ira-costs.c (find_costs_and_classes): Add extra argument.
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index 1dadfc57fec9..78614f8a2d77 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -2031,28 +2031,20 @@ nvptx_print_operand (FILE *file, rtx x, int code)
 	    fputs (".ne", file);
 	  break;
 	case LE:
+	case LEU:
 	  fputs (".le", file);
 	  break;
 	case GE:
+	case GEU:
 	  fputs (".ge", file);
 	  break;
 	case LT:
+	case LTU:
 	  fputs (".lt", file);
 	  break;
 	case GT:
-	  fputs (".gt", file);
-	  break;
-	case LEU:
-	  fputs (".ls", file);
-	  break;
-	case GEU:
-	  fputs (".hs", file);
-	  break;
-	case LTU:
-	  fputs (".lo", file);
-	  break;
 	case GTU:
-	  fputs (".hi", file);
+	  fputs (".gt", file);
 	  break;
 	case LTGT:
 	  fputs (".ne", file);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5229fa1868ff..6da1f381b6c2 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2016-02-02  Alexander Monakov  <amonakov@ispras.ru>
+
+	* gcc.target/nvptx/unsigned-cmp.c: New test.
+
 2016-02-02  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* gcc.target/aarch64/scalar_shift_1.c
diff --git a/gcc/testsuite/gcc.target/nvptx/unsigned-cmp.c b/gcc/testsuite/gcc.target/nvptx/unsigned-cmp.c
new file mode 100644
index 000000000000..a0cf5c2d4680
--- /dev/null
+++ b/gcc/testsuite/gcc.target/nvptx/unsigned-cmp.c
@@ -0,0 +1,50 @@
+/* { dg-options "-O2" } */
+/* { dg-do run } */
+
+/* nvptx backend used to emit lo/ls/hs/hi suffixes on unsigned comparison
+   insns instead of the more common lt/le/ge/gt, but ptxas and PTX JIT
+   miscompile 'ls' and 'hi' under some circumstances, such as when the first
+   source operand expands to a constant memory load, as demonstrated below.
+   Reported as NVIDIA bug ID 1725195 (tracker is not public).  */
+
+/* Define this to observe PTX translation breakage.  */
+//#define EMIT_BROKEN_ASM 1
+
+/* Or define this to get expected codegen.  */
+//#define EMIT_WORKING_ASM 1
+
+static __attribute__((noinline,noclone)) int ls(unsigned a)
+{
+    unsigned v;
+    /* %nctaid.x is always 1 in gcc testing.  */
+    asm ("mov.u32 %0, %%nctaid.x;" : "=r"(v));
+#if defined(EMIT_BROKEN_ASM)
+    asm ("set.u32.ls.u32 %0, %1, %0;" : "+r"(a) : "r"(v));
+#elif defined(EMIT_WORKING_ASM)
+    asm ("set.u32.le.u32 %0, %1, %0;" : "+r"(a) : "r"(v));
+#else
+    a = v <= a ? -1 : 0;
+#endif
+    return a;
+}
+static __attribute__((noinline,noclone)) int hi(unsigned a)
+{
+    unsigned v;
+    asm ("mov.u32 %0, %%nctaid.x;" : "=r"(v));
+#if defined(EMIT_BROKEN_ASM)
+    asm ("set.u32.hi.u32 %0, %1, %0;" : "+r"(a) : "r"(v));
+#elif defined(EMIT_WORKING_ASM)
+    asm ("set.u32.gt.u32 %0, %1, %0;" : "+r"(a) : "r"(v));
+#else
+    a = v > a ? -1 : 0;
+#endif
+    return a;
+}
+int main()
+{
+    int i;
+    for (i=0; i<3; i++)
+        if (ls(i) != -(1 <= i) || hi(i) != -(1 > i))
+            __builtin_abort();
+    return 0;
+}