Zero-initialise masked load destinations

Fixes an execution failure in testcase gfortran.dg/assumed_rank_1.f90.

2020-01-30  Andrew Stubbs  <ams@codesourcery.com>

	gcc/
	* config/gcn/gcn-valu.md (gather<mode>_exec): Move contents ...
	(mask_gather_load<mode>): ... here, and zero-initialize the
	destination.
	(maskload<mode>di): Zero-initialize the destination.
	* config/gcn/gcn.c:

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4e312cb8c3be55b088cc768042e389dc990f66f6..163afbae7789cd11238e1e7d99deb838833f0e5e 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2020-01-30  Andrew Stubbs  <ams@codesourcery.com>
+
+       * config/gcn/gcn-valu.md (gather<mode>_exec): Move contents ...
+       (mask_gather_load<mode>): ... here, and zero-initialize the
+       destination.
+       (maskload<mode>di): Zero-initialize the destination.
+       * config/gcn/gcn.c:
+
 2020-01-30  David Malcolm  <dmalcolm@redhat.com>
 
        PR analyzer/93356

diff --git a/gcc/config/gcn/gcn-valu.md b/gcc/config/gcn/gcn-valu.md
index 331c768cb882b57d82114e7818973ca387a86924..4aad835b2efc6416866a55c8f3ccd1c95ba98150 100644 (file)
--- a/gcc/config/gcn/gcn-valu.md
+++ b/gcc/config/gcn/gcn-valu.md
@@ -701,34 +701,6 @@
     DONE;
   })
 
-(define_expand "gather<mode>_exec"
-  [(match_operand:VEC_ALLREG_MODE 0 "register_operand")
-   (match_operand:DI 1 "register_operand")
-   (match_operand:V64SI 2 "register_operand")
-   (match_operand 3 "immediate_operand")
-   (match_operand:SI 4 "gcn_alu_operand")
-   (match_operand:DI 5 "gcn_exec_reg_operand")]
-  ""
-  {
-    rtx undefmode = gcn_gen_undef (<MODE>mode);
-
-    rtx addr = gcn_expand_scaled_offsets (DEFAULT_ADDR_SPACE, operands[1],
-                                         operands[2], operands[4],
-                                         INTVAL (operands[3]), operands[5]);
-
-    if (GET_MODE (addr) == V64DImode)
-      emit_insn (gen_gather<mode>_insn_1offset_exec (operands[0], addr,
-                                                    const0_rtx, const0_rtx,
-                                                    const0_rtx, undefmode,
-                                                    operands[5]));
-    else
-      emit_insn (gen_gather<mode>_insn_2offsets_exec (operands[0], operands[1],
-                                                     addr, const0_rtx,
-                                                     const0_rtx, const0_rtx,
-                                                     undefmode, operands[5]));
-    DONE;
-  })
-
 ; Allow any address expression
 (define_expand "gather<mode>_expr<exec>"
   [(set (match_operand:VEC_ALLREG_MODE 0 "register_operand")
@@ -2801,9 +2773,12 @@
                (<MODE>mode, exec, operands[1], gen_rtx_SCRATCH (V64DImode));
     rtx as = gen_rtx_CONST_INT (VOIDmode, MEM_ADDR_SPACE (operands[1]));
     rtx v = gen_rtx_CONST_INT (VOIDmode, MEM_VOLATILE_P (operands[1]));
-    rtx undef = gcn_gen_undef (<MODE>mode);
-    emit_insn (gen_gather<mode>_expr_exec (operands[0], addr, as, v, undef,
-                                          exec));
+
+    /* Masked lanes are required to hold zero.  */
+    emit_move_insn (operands[0], gcn_vec_constant (<MODE>mode, 0));
+
+    emit_insn (gen_gather<mode>_expr_exec (operands[0], addr, as, v,
+                                          operands[0], exec));
     DONE;
   })
 
@@ -2843,8 +2818,23 @@
        operands[2] = tmp;
       }
 
-    emit_insn (gen_gather<mode>_exec (operands[0], operands[1], operands[2],
-                                     operands[3], operands[4], exec));
+    rtx addr = gcn_expand_scaled_offsets (DEFAULT_ADDR_SPACE, operands[1],
+                                         operands[2], operands[4],
+                                         INTVAL (operands[3]), exec);
+
+    /* Masked lanes are required to hold zero.  */
+    emit_move_insn (operands[0], gcn_vec_constant (<MODE>mode, 0));
+
+    if (GET_MODE (addr) == V64DImode)
+      emit_insn (gen_gather<mode>_insn_1offset_exec (operands[0], addr,
+                                                    const0_rtx, const0_rtx,
+                                                    const0_rtx, operands[0],
+                                                    exec));
+    else
+      emit_insn (gen_gather<mode>_insn_2offsets_exec (operands[0], operands[1],
+                                                     addr, const0_rtx,
+                                                     const0_rtx, const0_rtx,
+                                                     operands[0], exec));
     DONE;
   })
 

diff --git a/gcc/config/gcn/gcn.c b/gcc/config/gcn/gcn.c
index a39e9f3fbd6d5731cf7147b593d913918954ea65..16c3aa2567eecc036c4c40c8c4bcf45cffff399f 100644 (file)
--- a/gcc/config/gcn/gcn.c
+++ b/gcc/config/gcn/gcn.c
@@ -992,9 +992,19 @@ gcn_vec_constant (machine_mode mode, int a)
     return CONST2_RTX (mode);*/
 
   int units = GET_MODE_NUNITS (mode);
-  rtx tem = gen_int_mode (a, GET_MODE_INNER (mode));
-  rtvec v = rtvec_alloc (units);
+  machine_mode innermode = GET_MODE_INNER (mode);
+
+  rtx tem;
+  if (FLOAT_MODE_P (innermode))
+    {
+      REAL_VALUE_TYPE rv;
+      real_from_integer (&rv, NULL, a, SIGNED);
+      tem = const_double_from_real_value (rv, innermode);
+    }
+  else
+    tem = gen_int_mode (a, innermode);
 
+  rtvec v = rtvec_alloc (units);
   for (int i = 0; i < units; ++i)
     RTVEC_ELT (v, i) = tem;