From 1ebd2fdc0da12397777ec4ea94f4ee0841ea244a Mon Sep 17 00:00:00 2001
From: Elliott Slaughter <slaughter@cs.stanford.edu>
Date: Thu, 31 May 2018 14:56:02 -0700
Subject: [PATCH] Revert "regent: Enable vectorization for scattered reads
 through opaque pointers"

This reverts commit c75ecf7ac50588e0e3f409ac404000c7bf112a6d.
---
 language/examples/pennant_fast.rg             | 60 +++++++++----------
 language/src/regent/codegen.t                 | 22 +------
 language/src/regent/vectorize_loops.t         | 12 ++--
 .../regent/compile_fail/vectorize_loops14.rg  |  6 +-
 .../regent/compile_fail/vectorize_loops15.rg  |  6 +-
 .../regent/compile_fail/vectorize_loops16.rg  |  6 +-
 .../regent/compile_fail/vectorize_loops17.rg  |  6 +-
 .../regent/compile_fail/vectorize_loops18.rg  |  6 +-
 .../regent/compile_fail/vectorize_loops19.rg  |  6 +-
 .../regent/compile_fail/vectorize_loops3.rg   |  4 +-
 10 files changed, 59 insertions(+), 75 deletions(-)

diff --git a/language/examples/pennant_fast.rg b/language/examples/pennant_fast.rg
index 52751eb8e5..6758d240bb 100644
--- a/language/examples/pennant_fast.rg
+++ b/language/examples/pennant_fast.rg
@@ -134,7 +134,7 @@ where
   reads(rz_spans)
 do
   for z_span in rz_spans do
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for z_raw = z_span.start, z_span.stop do
       var z = unsafe_cast(ptr(zone, rz), z_raw)
 
@@ -338,19 +338,19 @@ do
   for p_span in rp_spans do
     -- Save off point variable values from previous cycle.
     -- Initialize fields used in reductions.
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for p_raw = p_span.start, p_span.stop do
       var p = unsafe_cast(ptr(point, rp), p_raw)
 
       p.pmaswt = 0.0
     end
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for p_raw = p_span.start, p_span.stop do
       var p = unsafe_cast(ptr(point, rp), p_raw)
 
       p.pf.x = 0.0
     end
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for p_raw = p_span.start, p_span.stop do
       var p = unsafe_cast(ptr(point, rp), p_raw)
 
@@ -362,7 +362,7 @@ do
     --
 
     -- Copy state variables from previous time step and update position.
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for p_raw = p_span.start, p_span.stop do
       var p = unsafe_cast(ptr(point, rp), p_raw)
 
@@ -372,7 +372,7 @@ do
       p.pu0.x = pu0_x
       p.pxp.x = px0_x + dth*pu0_x
     end
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for p_raw = p_span.start, p_span.stop do
       var p = unsafe_cast(ptr(point, rp), p_raw)
 
@@ -449,7 +449,7 @@ do
 
     -- Save off zone variable value from previous cycle.
     -- Copy state variables from previous time step.
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for z_raw = z_span.start, z_span.stop do
       var z = unsafe_cast(ptr(zone, rz), z_raw)
 
@@ -613,7 +613,7 @@ do
     --
 
     -- Compute zone densities.
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for z_raw = z_span.start, z_span.stop do
       var z = unsafe_cast(ptr(zone, rz), z_raw)
 
@@ -622,7 +622,7 @@ do
 
     -- Reduce masses into points.
     if s_span.internal then
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -634,7 +634,7 @@ do
         p1.pmaswt += m
       end
     else
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -656,7 +656,7 @@ do
       var ss2 = max(ssmin * ssmin, 1e-99)
       var dth = 0.5 * dt
 
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for z_raw = z_span.start, z_span.stop do
         var z = unsafe_cast(ptr(zone, rz), z_raw)
 
@@ -683,7 +683,7 @@ do
     --
 
     -- Compute PolyGas and TTS forces.
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for s_raw = s_span.start, s_span.stop do
       var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -757,7 +757,7 @@ do
 
     -- QCS corner divergence.
     if s_span.internal then
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s2 = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -835,7 +835,7 @@ do
         c.cdu = cond3 * du
       end
     else
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s2 = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -918,7 +918,7 @@ do
     if s_span.internal then
       var gammap1 = gamma + 1.0
 
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s4 = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -945,7 +945,7 @@ do
     else
       var gammap1 = gamma + 1.0
 
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s4 = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -972,7 +972,7 @@ do
     end
 
     -- QCS force.
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for s_raw = s_span.start, s_span.stop do
       var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -999,14 +999,14 @@ do
 
     -- QCS vel diff.
     if s_span.internal then
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for z_raw = z_span.start, z_span.stop do
         var z = unsafe_cast(ptr(zone, rz), z_raw)
 
         z.z0tmp = 0.0
       end
 
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -1023,21 +1023,21 @@ do
         z.z0tmp max= dux
       end
 
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for z_raw = z_span.start, z_span.stop do
         var z = unsafe_cast(ptr(zone, rz), z_raw)
 
         z.zdu = q1 * z.zss + 2.0 * q2 * z.z0tmp
       end
     else
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for z_raw = z_span.start, z_span.stop do
         var z = unsafe_cast(ptr(zone, rz), z_raw)
 
         z.z0tmp = 0.0
       end
 
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -1054,7 +1054,7 @@ do
         z.z0tmp max= dux
       end
 
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for z_raw = z_span.start, z_span.stop do
         var z = unsafe_cast(ptr(zone, rz), z_raw)
 
@@ -1064,7 +1064,7 @@ do
 
     -- Reduce forces into points.
     if s_span.internal then
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -1076,7 +1076,7 @@ do
         p1.pf.y += f.y
       end
     else
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for s_raw = s_span.start, s_span.stop do
         var s = unsafe_cast(ptr(side(rz, rpp, rpg, rs), rs), s_raw)
 
@@ -1111,7 +1111,7 @@ do
     -- 4a. Apply boundary conditions.
     --
 
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for p_raw = p_span.start, p_span.stop do
       var p = unsafe_cast(ptr(point, rp), p_raw)
 
@@ -1131,7 +1131,7 @@ do
     do
       var fuzz = 1e-99
       var dth = 0.5 * dt
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for p_raw = p_span.start, p_span.stop do
         var p = unsafe_cast(ptr(point, rp), p_raw)
 
@@ -1364,7 +1364,7 @@ do
 
     do
       var dtiny = 1.0 / dt
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for z_raw = z_span.start, z_span.stop do
         var z = unsafe_cast(ptr(zone, rz), z_raw)
 
@@ -1379,7 +1379,7 @@ do
 
     do
       var fuzz = 1e-99
-      __demand(__vectorize)
+      --__demand(__vectorize)
       for z_raw = z_span.start, z_span.stop do
         var z = unsafe_cast(ptr(zone, rz), z_raw)
 
@@ -1387,7 +1387,7 @@ do
       end
     end
 
-    __demand(__vectorize)
+    --__demand(__vectorize)
     for z_raw = z_span.start, z_span.stop do
       var z = unsafe_cast(ptr(zone, rz), z_raw)
 
diff --git a/language/src/regent/codegen.t b/language/src/regent/codegen.t
index b3ba3d0bab..935ea1de4e 100644
--- a/language/src/regent/codegen.t
+++ b/language/src/regent/codegen.t
@@ -1023,12 +1023,7 @@ function ref:__ref(cx, expr_type)
     values = data.zip(field_types, base_pointers, strides):map(
       function(field)
         local field_type, base_pointer, stride = unpack(field)
-        local vec
-        if std.type_eq(field_type, std.ptr) then
-          vec = expr_type.impl_type
-        else
-          vec = vector(field_type, std.as_read(expr_type).N)
-        end
+        local vec = vector(field_type, std.as_read(expr_type).N)
         return `(@[&vec](&[get_element_pointer(cx, self.node, region_types, self.value_type, field_type, base_pointer, stride, value)]))
       end)
     value_type = expr_type
@@ -1089,10 +1084,6 @@ function ref:write(cx, value, expr_type)
          for _, field_name in ipairs(field_path) do
            result = `([result].[field_name])
          end
-         if std.is_vptr(expr_type) and std.type_eq(field_type, std.ptr) then
-           field_value = `([field_value].value)
-           result = `([result].__ptr.value)
-         end
          if expr_type and
             (expr_type:isvector() or
              std.is_vptr(expr_type) or
@@ -1322,9 +1313,8 @@ function vref:read(cx, expr_type)
   actions = quote
     [actions];
     var [value]
-    [data.zip(field_paths, field_types):map(
-       function(pair)
-         local field_path, field_type = unpack(pair)
+    [field_paths:map(
+       function(field_path)
          local result = value
          local field_accesses = vars:map(
           function(v)
@@ -1336,12 +1326,6 @@ function vref:read(cx, expr_type)
          for _, field_name in ipairs(field_path) do
            result = `([result].[field_name])
          end
-         if std.is_vptr(expr_type) and std.type_eq(field_type, ptr) then
-           result = `([result].value)
-           field_accesses = field_accesses:map(function(field_access)
-             return `([field_access].__ptr.value)
-           end)
-         end
          return quote [result] = vector( [field_accesses] ) end
        end)]
   end
diff --git a/language/src/regent/vectorize_loops.t b/language/src/regent/vectorize_loops.t
index 0328fb1194..ded1506f40 100644
--- a/language/src/regent/vectorize_loops.t
+++ b/language/src/regent/vectorize_loops.t
@@ -838,16 +838,16 @@ function check_vectorizability.expr(cx, node)
 
     if cx:lookup_expr_type(node.index) == V then
       local value_type = std.as_read(node.value.expr_type)
-      ---- TODO: We currently don't support scattered reads from structured regions
-      ----       Update on 06/20/17: index types are no longer sliced. will reject
-      ----                           all scattered reads for now. (wclee)
+      -- TODO: We currently don't support scattered reads from structured regions
+      --       Update on 06/20/17: index types are no longer sliced. will reject
+      --                           all scattered reads for now. (wclee)
       if std.is_region(value_type) then
         cx:report_error_when_demanded(node, error_prefix ..
           "a scattered read from a structured region")
         return false
       -- TODO: This should be supported
       elseif std.is_region(value_type) and value_type:is_opaque() and
-         not std.is_bounded_type(std.as_read(node.index.expr_type)) then
+             not std.is_bounded_type(std.as_read(node.index.expr_type)) then
         cx:report_error_when_demanded(node, error_prefix ..
           "a scattered read from a different region")
         return false
@@ -943,7 +943,7 @@ function check_vectorizability.expr(cx, node)
     -- TODO: We currently don't support scattered reads from structured regions
     --       Update on 06/20/17: index types are no longer sliced. will reject
     --                           all scattered reads for now. (wclee)
-    elseif fact == V and not std.as_read(node.value.expr_type).index_type:is_opaque() then
+    elseif fact == V then
       cx:report_error_when_demanded(node, error_prefix ..
         "a scattered read from a structured region")
       return false
@@ -1049,7 +1049,7 @@ end
 function check_vectorizability.type(ty)
   if (std.is_bounded_type(ty) and std.is_index_type(ty.index_type)) or
      std.is_index_type(ty) or std.is_rect_type(ty) then
-    return ty.dim == 0
+    return false
   elseif ty:isprimitive() then
     return true
   elseif ty:isstruct() then
diff --git a/language/tests/regent/compile_fail/vectorize_loops14.rg b/language/tests/regent/compile_fail/vectorize_loops14.rg
index 0bee6292ab..4b6f331e63 100644
--- a/language/tests/regent/compile_fail/vectorize_loops14.rg
+++ b/language/tests/regent/compile_fail/vectorize_loops14.rg
@@ -13,9 +13,9 @@
 -- limitations under the License.
 
 -- fails-with:
--- vectorize_loops14.rg:45: vectorization failed: loop body has aliasing update of path region(fs3()).v
---     e.p1.p.v += e.p2.p.v
---     ^
+-- vectorize_loops14.rg:45: vectorization failed: loop body has a scattered read from a structured region
+-- e.p1.p.v += e.p2.p.v
+-- ^
 
 import "regent"
 
diff --git a/language/tests/regent/compile_fail/vectorize_loops15.rg b/language/tests/regent/compile_fail/vectorize_loops15.rg
index 6ed532aab0..c1a49d14d1 100644
--- a/language/tests/regent/compile_fail/vectorize_loops15.rg
+++ b/language/tests/regent/compile_fail/vectorize_loops15.rg
@@ -13,9 +13,9 @@
 -- limitations under the License.
 
 -- fails-with:
--- vectorize_loops15.rg:40: vectorization failed: loop body has aliasing update of path region(fs2()).v
---     e.p1.v = e.p2.v
---     ^
+-- vectorize_loops15.rg:40: vectorization failed: loop body has a scattered read from a structured region
+-- e.p1.v = e.p2.v
+-- ^
 
 import "regent"
 
diff --git a/language/tests/regent/compile_fail/vectorize_loops16.rg b/language/tests/regent/compile_fail/vectorize_loops16.rg
index be5311b549..d21404843e 100644
--- a/language/tests/regent/compile_fail/vectorize_loops16.rg
+++ b/language/tests/regent/compile_fail/vectorize_loops16.rg
@@ -13,9 +13,9 @@
 -- limitations under the License.
 
 -- fails-with:
--- vectorize_loops16.rg:40: vectorization failed: loop body has aliasing update of path region(fs2()).v
---     e.p2.v = e.p1.v
---     ^
+-- vectorize_loops16.rg:40: vectorization failed: loop body has a scattered read from a structured region
+-- e.p2.v = e.p1.v
+-- ^
 
 import "regent"
 
diff --git a/language/tests/regent/compile_fail/vectorize_loops17.rg b/language/tests/regent/compile_fail/vectorize_loops17.rg
index fdfc79fa7b..6a2e5fe300 100644
--- a/language/tests/regent/compile_fail/vectorize_loops17.rg
+++ b/language/tests/regent/compile_fail/vectorize_loops17.rg
@@ -13,9 +13,9 @@
 -- limitations under the License.
 
 -- fails-with:
--- vectorize_loops17.rg:41: vectorization failed: loop body has aliasing update of path region(fs2()).v
---     e.p1.v = t
---     ^
+-- vectorize_loops17.rg:40: vectorization failed: loop body has a scattered read from a structured region
+--     var t = e.p2.v
+--              ^
 
 import "regent"
 
diff --git a/language/tests/regent/compile_fail/vectorize_loops18.rg b/language/tests/regent/compile_fail/vectorize_loops18.rg
index 45aa0fc180..375609e180 100644
--- a/language/tests/regent/compile_fail/vectorize_loops18.rg
+++ b/language/tests/regent/compile_fail/vectorize_loops18.rg
@@ -13,9 +13,9 @@
 -- limitations under the License.
 
 -- fails-with:
--- vectorize_loops18.rg:42: vectorization failed: loop body has aliasing update of path region(fs2()).v
---       e.p1.v += t
---       ^
+-- vectorize_loops18.rg:40: vectorization failed: loop body has a scattered read from a structured region
+--     var t = e.p2.v
+--              ^
 
 import "regent"
 
diff --git a/language/tests/regent/compile_fail/vectorize_loops19.rg b/language/tests/regent/compile_fail/vectorize_loops19.rg
index 3c39ed5061..bcc5ca8699 100644
--- a/language/tests/regent/compile_fail/vectorize_loops19.rg
+++ b/language/tests/regent/compile_fail/vectorize_loops19.rg
@@ -13,9 +13,9 @@
 -- limitations under the License.
 
 -- fails-with:
--- vectorize_loops19.rg:42: vectorization failed: loop body has aliasing update of path region(fs2()).v
---       e.p1.v += t
---       ^
+-- vectorize_loops19.rg:42: vectorization failed: loop body has a scattered read from a structured region
+-- e.p1.v += t
+-- ^
 
 import "regent"
 
diff --git a/language/tests/regent/compile_fail/vectorize_loops3.rg b/language/tests/regent/compile_fail/vectorize_loops3.rg
index 8072e386db..7ab73b59c0 100644
--- a/language/tests/regent/compile_fail/vectorize_loops3.rg
+++ b/language/tests/regent/compile_fail/vectorize_loops3.rg
@@ -13,9 +13,9 @@
 -- limitations under the License.
 
 -- fails-with:
--- vectorize_loops3.rg:40: vectorization failed: loop body has aliasing update of path region(fs2()).v
+-- vectorize_loops3.rg:40: vectorization failed: loop body has a scattered read from a structured region
 --     e.p1.v = e.p2.v
---     ^
+--      ^
 
 import "regent"