Changes between Version 36 and Version 37 of Next-GenOpenMPTransformation

Timestamp:

10/29/19 17:31:09 (7 years ago)

Author:

wuwenhao

Comment:

--

Next-GenOpenMPTransformation

@@ -397 +397 @@
 == Translations of specific directives ==
 [https://vsl.cis.udel.edu/trac/civl/wiki/Next-GenOpenMPTransformation#Translatingparallel 1. parallel construct]\\
-[https://vsl.cis.udel.edu/trac/civl/wiki/Next-GenOpenMPTransformation#Translatingfor 2. worksharing-loop construct]\\
+[https://vsl.cis.udel.edu/trac/civl/wiki/Next-GenOpenMPTransformation#Translatingsections 2. worksharing sections construct]\\
+[https://vsl.cis.udel.edu/trac/civl/wiki/Next-GenOpenMPTransformation#Translatingsingle 3. worksharing single construct]\\
+[https://vsl.cis.udel.edu/trac/civl/wiki/Next-GenOpenMPTransformation#Translatingfor 4. worksharing loop construct]\\
 
 === Translating `parallel` ===
@@ -454 +456 @@
 Otherwise, `i` (in the `$parfor`) is uninitialized, so has an undefined value.
 
+=== Translating `sections` ===
+
+Say there are `numSections` sections.  This number is known statically.
+
+{{{
+#pragma omp sections
+#pragma omp section
+  S1 // section 1
+#pragma omp section
+  S2 // section 2
+...
+}}}
+
+=>
+
+{{{
+{
+  $domain(1) sections_dist = $omp_arrive_sections(
+               team, section_id++, numSections);
+
+  $for (int _omp_sid : sections_dist) {
+    if(_omp_sid == 1) { // section 1
+      translate(S1);
+    }
+    if(_omp_sid == 2) { // section 2
+      translate(S2);
+    }
+    ...
+  }
+  $omp_barrier_and_flush();
+}
+}}}
+
+=== Translating `single` ===
+
+{{{
+#pragma omp single
+  BLOCK
+}}}
+
+=>
+
+{{{
+{ // single construct (begin)
+  int _omp_single_dist = $omp_arrive_single(
+        team, single_id++);
+
+  if (_omp_tid == _omp_single_dist) {
+    translate(S);
+  }
+
+  $omp_barrier_and_flush(team);
+} // single construct (end)
+}}}
+
 === Translating `for` ===
 
@@ -501 +558 @@
                team, loop_id++, loop_domain, STRATEGY);
 
-  $for (int i, j, k : my_iters) {
+  $for (int i, j, k : loop_dist) {
     transfromed(BLOCK)
   }
@@ -510 +567 @@
 === Translating `reduction` clause ===
 
-{{{
-#pragma omp for reduction(+:x,y)
-for (i=a; i<b; i++) {
-  S
-}
-}}}
-
-=>
-
-
-{{{
+==== Case 1: parallel reduction ====
+{{{
+int sum = sum_base;
+int prod = prod_base;
+
+#pragma parallel shared(a) reduction(+:sum) reduction(*:prod)
 {
-  $domain loop_domain = {a..b-1};
-  $domain(1) my_iters = ($domain(1))$omp_arrive_loop(team, FOR_LOC++, loop_domain, STRATEGY);
-  double _x=0.0, _y=0.0; // not the local view of the shared variable x/y
-
-  $for (int i : my_iters) {
-    translate(S) but replace x with _x and y with _y;
-  }
-  $omp_apply_assoc(x_shared, CIVL_SUM, &_x);
-  $omp_apply_assoc(y_shared, CIVL_SUM, &_y);
+  int tid = omp_get_thread_num();
+
+  sum += a[tid];
+  prod *= a[tid];
+}
+}}}
+
+=>
+
+{{{
+int sum = sum_base;
+int prod = prod_base;
+
+{ // parallel construct (begin)
+  ..
+  $parfor (..) {
+    ..
+    int *_omp_rdc_0_sum = &sum;
+    int sum = 0;
+    int *_omp_rdc_1_prod = &prod;
+    int prod = 1;
+    
+    int tid = _omp_tid;
+    
+    sum += a[tid];
+    prod *= a[tid];   
+
+    $omp_reduction_combine(ADD, _omp_rdc_0_sum, sum);
+    $omp_reduction_combine(MULT, _omp_rdc_1_prod, prod);
+
+    $omp_barrier_and_flush(team); //check data race
+    ..
+  }
+  ..
+} // parallel construct (end)
+}}}
+
+==== Case 2: for reduction ====
+
+{{{
+#pragma omp for reduction(+: fsum, isum) 
+for (i=a; i<b; i+=c) {
+  BLOCK
+  fsum += EXPR0;
+  isum += EXPR1;
+}
+}}}
+
+=>
+
+{{{
+{ // worksharing-loop construct (begin)
+  $domain loop_domain = {a..b-1#c};
+  $domain(1) loop_dist = ($domain(1))$omp_arrive_loop(
+               team, loop_id++, loop_domain, STRATEGY);
+  
+  float *_omp_rdc_0_fsum = &fsum;
+  float fsum = 0.0;
+  int *_omp_rdc_1_isum = &isum;
+  int isum = 0;
+
+  $for (int i : loop_dist) {
+    translate(BLOCK)
+    fsum += translate(EXPR0);
+    isum += translate(EXPR1);
+  }
+
+  $omp_reduction_combine(ADD, _omp_rdc_0_fsum, fsum);
+  $omp_reduction_combine(ADD, _omp_rdc_1_isum, isum);
+
   $omp_barrier_and_flush(team);
-}
-}}}
-
-
-
-=== Translating `sections` ===
-
-Say there are `numSections` sections.  This number is known statically.
-
-{{{
-#pragma omp sections
-#pragma omp section
-  S0 // section 1
-#pragma omp section
-  S1 // section 2
-...
-}}}
-
-=>
-
-{{{
-{
-  $domain(1) my_secs = $omp_arrive_sections(team, section_id++, numSections);
-
-  $for (int i : my_secs) {
-    
-    if(section_id == 1) {
-      translate(S0);
-    } 
-    if(section_id == 2) {
-      translate(S0);
-    }
-    ...
-    } /* end of switch */
-  } /* end of $for loop */
-  $omp_barrier_and_flush();
-}
-}}}
-
-
-=== Translating `single` ===
-
-{{{
-#pragma omp single
-S
-}}}
-
-=>
-
-{{{
-int owner = $omp_arrive_single(team, SINGLE_LOC++);
-
-if (owner == _tid) {
-  translate(S);
-}
-$omp_barrier_and_flush(team);
-}}}
-
+} // worksharing-loop construct (end)
+}}}
+
+In `Case1` the combination is performed in `$parfor` after the completion of 
+the last statement in the original structured block.
+In `Case2` the combination is performed immediately after the end of `$for`.
 
 === Translating `barrier` ===