[PPCGCodeGen] Fix compiler warning: '<': signed/unsigned mismatch. NFC.

MSVC warns about comparison between a signed and unsigned integer.
The rules of C(++) define that an unsigned comparison has to be
carried-out in this case. This is unlikely to be intended.

Fix by assigning the loop's upper bound to a signed integer first.
This also avoids repeated evaluation of the invariant upper bound.

llvm-svn: 311548

1 files changed, 6 insertions, 6 deletions

diff --git a/polly/lib/CodeGen/PPCGCodeGeneration.cpp b/polly/lib/CodeGen/PPCGCodeGeneration.cpp
index 28fa9e6b553c..41e1c9ecd0f9 100644
--- a/polly/lib/CodeGen/PPCGCodeGeneration.cpp
+++ b/polly/lib/CodeGen/PPCGCodeGeneration.cpp
@@ -1131,7 +1131,7 @@ Value *GPUNodeBuilder::getArrayOffset(gpu_array_info *Array) {
 
   isl::set ZeroSet = isl::set::universe(Min.get_space());
 
-  for (long i = 0; i < Min.dim(isl::dim::set); i++)
+  for (long i = 0, n = Min.dim(isl::dim::set); i < n; i++)
     ZeroSet = ZeroSet.fix_si(isl::dim::set, i, 0);
 
   if (Min.is_subset(ZeroSet)) {
@@ -1140,7 +1140,7 @@ Value *GPUNodeBuilder::getArrayOffset(gpu_array_info *Array) {
 
   isl::ast_expr Result = isl::ast_expr::from_val(isl::val(Min.get_ctx(), 0));
 
-  for (long i = 0; i < Min.dim(isl::dim::set); i++) {
+  for (long i = 0, n = Min.dim(isl::dim::set); i < n; i++) {
     if (i > 0) {
       isl::pw_aff Bound_I =
           isl::manage(isl_multi_pw_aff_get_pw_aff(Array->bound, i - 1));
@@ -1473,7 +1473,7 @@ GPUNodeBuilder::getReferencesInKernel(ppcg_kernel *Kernel) {
     SubtreeValues.remove(SAI->getBasePtr());
 
   isl_space *Space = S.getParamSpace().release();
-  for (long i = 0; i < isl_space_dim(Space, isl_dim_param); i++) {
+  for (long i = 0, n = isl_space_dim(Space, isl_dim_param); i < n; i++) {
     isl_id *Id = isl_space_get_dim_id(Space, isl_dim_param, i);
     assert(IDToValue.count(Id));
     Value *Val = IDToValue[Id];
@@ -1482,7 +1482,7 @@ GPUNodeBuilder::getReferencesInKernel(ppcg_kernel *Kernel) {
   }
   isl_space_free(Space);
 
-  for (long i = 0; i < isl_space_dim(Kernel->space, isl_dim_set); i++) {
+  for (long i = 0, n = isl_space_dim(Kernel->space, isl_dim_set); i < n; i++) {
     isl_id *Id = isl_space_get_dim_id(Kernel->space, isl_dim_set, i);
     assert(IDToValue.count(Id));
     Value *Val = IDToValue[Id];
@@ -1991,7 +1991,7 @@ GPUNodeBuilder::createKernelFunctionDecl(ppcg_kernel *Kernel,
     isl_ast_build *Build =
         isl_ast_build_from_context(isl_set_copy(Prog->context));
     Sizes.push_back(nullptr);
-    for (long j = 1; j < Kernel->array[i].array->n_index; j++) {
+    for (long j = 1, n = Kernel->array[i].array->n_index; j < n; j++) {
       isl_ast_expr *DimSize = isl_ast_build_expr_from_pw_aff(
           Build, isl_multi_pw_aff_get_pw_aff(Kernel->array[i].array->bound, j));
       auto V = ExprBuilder.create(DimSize);
@@ -3246,7 +3246,7 @@ public:
     auto *Univ = isl_set_universe(Space);
     isl_pw_aff *OneAff = isl_pw_aff_val_on_domain(Univ, One);
 
-    for (long i = 0; i < isl_set_dim(Set, isl_dim_set); i++) {
+    for (long i = 0, n = isl_set_dim(Set, isl_dim_set); i < n; i++) {
       isl_pw_aff *Max = isl_set_dim_max(isl_set_copy(Set), i);
       isl_pw_aff *Min = isl_set_dim_min(isl_set_copy(Set), i);
       isl_pw_aff *DimSize = isl_pw_aff_sub(Max, Min);