[polly] r239024 - Ensure memory access mappings are defined for full domain
Tobias Grosser
tobias at grosser.es
Thu Jun 4 00:44:35 PDT 2015
Author: grosser
Date: Thu Jun 4 02:44:35 2015
New Revision: 239024
URL: http://llvm.org/viewvc/llvm-project?rev=239024&view=rev
Log:
Ensure memory access mappings are defined for full domain
We now verify that memory access functions imported via JSON are indeed defined
for the full iteration domain. Before this change we accidentally imported
memory mappings such as i -> i / 127, which only defined a mapped for values of
i that are evenly divisible by 127, but which did not define any mapping for the
remaining values, with the result that isl just generated an access expression
that had undefined behavior for all the unmapped values.
In the incorrect test cases, we now either use floor(i/127) or we use p/127 and
provide the information that p is indeed a multiple of 127.
Modified:
polly/trunk/lib/Exchange/JSONExporter.cpp
polly/trunk/test/Isl/CodeGen/exprModDiv.ll
polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop
polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop.pow2
Modified: polly/trunk/lib/Exchange/JSONExporter.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Exchange/JSONExporter.cpp?rev=239024&r1=239023&r2=239024&view=diff
==============================================================================
--- polly/trunk/lib/Exchange/JSONExporter.cpp (original)
+++ polly/trunk/lib/Exchange/JSONExporter.cpp Thu Jun 4 02:44:35 2015
@@ -343,6 +343,28 @@ bool JSONImporter::runOnScop(Scop &S) {
isl_map_free(newAccessMap);
return false;
}
+
+ auto NewAccessDomain = isl_map_domain(isl_map_copy(newAccessMap));
+ auto CurrentAccessDomain = isl_map_domain(isl_map_copy(currentAccessMap));
+
+ NewAccessDomain =
+ isl_set_intersect_params(NewAccessDomain, S.getContext());
+ CurrentAccessDomain =
+ isl_set_intersect_params(CurrentAccessDomain, S.getContext());
+
+ if (isl_set_is_subset(CurrentAccessDomain, NewAccessDomain) ==
+ isl_bool_false) {
+ errs() << "Mapping not defined for all iteration domain elements\n";
+ isl_set_free(CurrentAccessDomain);
+ isl_set_free(NewAccessDomain);
+ isl_map_free(currentAccessMap);
+ isl_map_free(newAccessMap);
+ return false;
+ }
+
+ isl_set_free(CurrentAccessDomain);
+ isl_set_free(NewAccessDomain);
+
if (!isl_map_is_equal(newAccessMap, currentAccessMap)) {
// Statistics.
++NewAccessMapFound;
Modified: polly/trunk/test/Isl/CodeGen/exprModDiv.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/Isl/CodeGen/exprModDiv.ll?rev=239024&r1=239023&r2=239024&view=diff
==============================================================================
--- polly/trunk/test/Isl/CodeGen/exprModDiv.ll (original)
+++ polly/trunk/test/Isl/CodeGen/exprModDiv.ll Thu Jun 4 02:44:35 2015
@@ -17,11 +17,15 @@
; CHECK: %pexp.pdiv_r = urem i64 %polly.indvar, 127
; CHECK: %polly.access.A6 = getelementptr float, float* %A, i64 %pexp.pdiv_r
-; A[i / 127]
-; CHECK: %pexp.div = sdiv i64 %polly.indvar, 127
-; CHECK: %polly.access.B8 = getelementptr float, float* %B, i64 %pexp.div
+; A[floor(i / 127)]
;
-; FIXME: Make isl mark this as an udiv expression.
+; Note: without the floor, we would create a map i -> i/127, which only contains
+; values of i that are divisible by 127. All other values of i would not
+; be mapped to any value. However, to generate correct code we require
+; each value of i to indeed be mapped to a value.
+;
+; CHECK: %pexp.p_div_q = udiv i64 %polly.indvar, 127
+; CHECK: %polly.access.B8 = getelementptr float, float* %B, i64 %pexp.p_div_q
; #define floord(n,d) ((n < 0) ? (n - d + 1) : n) / d
; A[p + 127 * floord(-p - 1, 127) + 127]
@@ -38,16 +42,16 @@
; CHECK: %polly.access.A10 = getelementptr float, float* %A, i64 %24
; A[p / 127]
-; CHECK: %pexp.div12 = sdiv i64 %p, 127
-; CHECK: %polly.access.B13 = getelementptr float, float* %B, i64 %pexp.div12
+; CHECK: %pexp.div = sdiv i64 %p, 127
+; CHECK: %polly.access.B12 = getelementptr float, float* %B, i64 %pexp.div
; A[i % 128]
; POW2: %pexp.pdiv_r = urem i64 %polly.indvar, 128
; POW2: %polly.access.A6 = getelementptr float, float* %A, i64 %pexp.pdiv_r
-; A[i / 128]
-; POW2: %pexp.div.shr = ashr i64 %polly.indvar, 7
-; POW2: %polly.access.B8 = getelementptr float, float* %B, i64 %pexp.div
+; A[floor(i / 128)]
+; POW2: %pexp.p_div_q = udiv i64 %polly.indvar, 128
+; POW2: %polly.access.B8 = getelementptr float, float* %B, i64 %pexp.p_div_q
; #define floord(n,d) ((n < 0) ? (n - d + 1) : n) / d
; A[p + 128 * floord(-p - 1, 128) + 128]
@@ -60,8 +64,8 @@
; POW2: %polly.access.A10 = getelementptr float, float* %A, i64 %24
; A[p / 128]
-; POW2: %pexp.div.shr12 = ashr i64 %p, 7
-; POW2: %polly.access.B13 = getelementptr float, float* %B, i64 %pexp.div.shr12
+; POW2: %pexp.div.shr = ashr i64 %p, 7
+; POW2: %polly.access.B12 = getelementptr float, float* %B, i64 %pexp.div.shr
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
Modified: polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/Isl/CodeGen/exprModDiv___%25for.cond---%25for.end.jscop?rev=239024&r1=239023&r2=239024&view=diff
==============================================================================
--- polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop (original)
+++ polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop Thu Jun 4 02:44:35 2015
@@ -1,5 +1,5 @@
{
- "context" : "[N, p] -> { : N >= -9223372036854775808 and N <= 9223372036854775807 and p >= -9223372036854775808 and p <= 9223372036854775807 }",
+ "context" : "[N, p] -> { : N >= -9223372036854775808 and N <= 9223372036854775807 and p >= -9223372036854775808 and p <= 9223372036854775807 and (p % 127) = 0}",
"name" : "for.cond => for.end",
"statements" : [
{
@@ -10,7 +10,7 @@
},
{
"kind" : "read",
- "relation" : "[N, p] -> { Stmt_for_body[i0] -> MemRef_B[i0 / 127] }"
+ "relation" : "[N, p] -> { Stmt_for_body[i0] -> MemRef_B[floor(i0 / 127)] }"
},
{
"kind" : "read",
Modified: polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop.pow2
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/Isl/CodeGen/exprModDiv___%25for.cond---%25for.end.jscop.pow2?rev=239024&r1=239023&r2=239024&view=diff
==============================================================================
--- polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop.pow2 (original)
+++ polly/trunk/test/Isl/CodeGen/exprModDiv___%for.cond---%for.end.jscop.pow2 Thu Jun 4 02:44:35 2015
@@ -1,5 +1,5 @@
{
- "context" : "[N, p] -> { : N >= -9223372036854775808 and N <= 9223372036854775807 and p >= -9223372036854775808 and p <= 9223372036854775807 }",
+ "context" : "[N, p] -> { : N >= -9223372036854775808 and N <= 9223372036854775807 and p >= -9223372036854775808 and p <= 9223372036854775807 and p % 128 = 0}",
"name" : "for.cond => for.end",
"statements" : [
{
@@ -10,7 +10,7 @@
},
{
"kind" : "read",
- "relation" : "[N, p] -> { Stmt_for_body[i0] -> MemRef_B[i0 / 128] }"
+ "relation" : "[N, p] -> { Stmt_for_body[i0] -> MemRef_B[floor(i0 / 128)] }"
},
{
"kind" : "read",
More information about the llvm-commits
mailing list