[nvptx] Fix bug in jit bug workaround

2018-01-19  Tom de Vries  <tom@codesourcery.com>
	    Cesar Philippidis  <cesar@codesourcery.com>

	PR target/83920

	* config/nvptx/nvptx.c (nvptx_single): Fix jit workaround.

	* testsuite/libgomp.oacc-c-c++-common/pr83920.c: New test.
	* testsuite/libgomp.oacc-fortran/pr83920.f90: New test.

Co-Authored-By: Cesar Philippidis <cesar@codesourcery.com>

From-SVN: r256894

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2018-01-19  Tom de Vries  <tom@codesourcery.com>
+	    Cesar Philippidis  <cesar@codesourcery.com>
+
+	PR target/83920
+	* config/nvptx/nvptx.c (nvptx_single): Fix jit workaround.
+
 2018-01-19  Cesar Philippidis  <cesar@codesourcery.com>
 
 	PR target/83790

gcc/config/nvptx/nvptx.c

@@ -4102,9 +4102,33 @@ nvptx_single (unsigned mask, basic_block from, basic_block to)
 
 	     There is nothing in the PTX spec to suggest that this is wrong, or
 	     to explain why the extra initialization is needed.  So, we classify
-	     it as a JIT bug, and the extra initialization as workaround.  */
-	  emit_insn_before (gen_movbi (pvar, const0_rtx),
+	     it as a JIT bug, and the extra initialization as workaround:
+
+		{
+		    .reg .u32 %x;
+		    mov.u32 %x,%tid.x;
+		    setp.ne.u32 %rnotvzero,%x,0;
+		}
+
+		+.reg .pred %rcond2;
+		+setp.eq.u32 %rcond2, 1, 0;
+
+		 @%rnotvzero bra Lskip;
+		 setp.<op>.<type> %rcond,op1,op2;
+		+mov.pred %rcond2, %rcond;
+		 Lskip:
+		+mov.pred %rcond, %rcond2;
+		 selp.u32 %rcondu32,1,0,%rcond;
+		 shfl.idx.b32 %rcondu32,%rcondu32,0,31;
+		 setp.ne.u32 %rcond,%rcondu32,0;
+	  */
+	  rtx_insn *label = PREV_INSN (tail);
+	  gcc_assert (label && LABEL_P (label));
+	  rtx tmp = gen_reg_rtx (BImode);
+	  emit_insn_before (gen_movbi (tmp, const0_rtx),
 			    bb_first_real_insn (from));
+	  emit_insn_before (gen_rtx_SET (tmp, pvar), label);
+	  emit_insn_before (gen_rtx_SET (pvar, tmp), tail);
 #endif
 	  emit_insn_before (nvptx_gen_vcast (pvar), tail);
 	}

libgomp/ChangeLog

@@ -1,3 +1,10 @@
+2018-01-19  Tom de Vries  <tom@codesourcery.com>
+	    Cesar Philippidis  <cesar@codesourcery.com>
+
+	PR target/83920
+	* testsuite/libgomp.oacc-c-c++-common/pr83920.c: New test.
+	* testsuite/libgomp.oacc-fortran/pr83920.f90: New test.
+
 2018-01-03  Jakub Jelinek  <jakub@redhat.com>
 
 	Update copyright years.

libgomp/testsuite/libgomp.oacc-c-c++-common/pr83920.c

@@ -0,0 +1,32 @@
+/* { dg-do run } */
+
+#include <stdlib.h>
+
+#define n 10
+
+static void __attribute__((noinline)) __attribute__((noclone))
+foo (int beta, int *c)
+{
+  #pragma acc parallel copy(c[0:(n * n) - 1]) num_gangs(2)
+  #pragma acc loop gang
+  for (int j = 0; j < n; ++j)
+    if (beta != 1)
+      {
+        #pragma acc loop vector
+	for (int i = 0; i < n; ++i)
+	  c[i + (j * n)] = 0;
+      }
+}
+
+int
+main (void)
+{
+  int c[n * n];
+
+  c[0] = 1;
+  foo (0, c);
+  if (c[0] != 0)
+    abort ();
+
+  return 0;
+}

libgomp/testsuite/libgomp.oacc-fortran/pr83920.f90

@@ -0,0 +1,28 @@
+! { dg-do run }
+
+subroutine foo (BETA, C)
+  real ::  C(100,100)
+  integer :: i, j, l
+  real, parameter :: one = 1.0
+  real :: beta
+
+  !$acc parallel copy(c(1:100,1:100)) num_gangs(2)
+  !$acc loop gang
+  do j = 1, 100
+     if (beta /= one) then
+        !$acc loop vector
+        do i = 1, 100
+           C(i,j) = 0.0
+        end do
+     end if
+  end do
+  !$acc end parallel
+end subroutine foo
+
+program test_foo
+  real :: c(100,100), beta
+  beta = 0.0
+  c(:,:) = 1.0
+  call foo (beta, c)
+  if (c(1,1) /= 0.0) call abort ()
+end program test_foo