commit 67701712d90d62da58fe72e58f83f81d98fbc986
author Uday Bondhugula <bondhugula@google.com> Tue Aug 21 16:01:23 2018 -0700
committer jpienaar <jpienaar@google.com> Fri Mar 29 13:03:38 2019 -0700
tree 92647ea626f46843a8712a4c5df31d2a65d267ae
parent 257339b552f534615a65b0fae9fb816d3ea2f4f2

Extend loop unrolling to unroll by a given factor; add builder for affine
apply op.

- add builder for AffineApplyOp (first one for an operation that has
  non-zero operands)
- add support for loop unrolling by a given factor; uses the affine apply op
  builder.

While on this, change 'step' of ForStmt to be 'unsigned' instead of
AffineConstantExpr *. Add setters for ForStmt lb, ub, step.

Sample Input:

// CHECK-LABEL: mlfunc @loop_nest_unroll_cleanup() {
mlfunc @loop_nest_unroll_cleanup() {
  for %i = 1 to 100 {
    for %j = 0 to 17 {
      %x = "addi32"(%j, %j) : (affineint, affineint) -> i32
      %y = "addi32"(%x, %x) : (i32, i32) -> i32
    }
  }
  return
}

Output:

$ mlir-opt -loop-unroll -unroll-factor=4 /tmp/single2.mlir
#map0 = (d0) -> (d0 + 1)
#map1 = (d0) -> (d0 + 2)
#map2 = (d0) -> (d0 + 3)
mlfunc @loop_nest_unroll_cleanup() {
  for %i0 = 1 to 100 {
    for %i1 = 0 to 17 step 4 {
      %0 = "addi32"(%i1, %i1) : (affineint, affineint) -> i32
      %1 = "addi32"(%0, %0) : (i32, i32) -> i32
      %2 = affine_apply #map0(%i1)
      %3 = "addi32"(%2, %2) : (affineint, affineint) -> i32
      %4 = affine_apply #map1(%i1)
      %5 = "addi32"(%4, %4) : (affineint, affineint) -> i32
      %6 = affine_apply #map2(%i1)
      %7 = "addi32"(%6, %6) : (affineint, affineint) -> i32
    }
    for %i2 = 16 to 17 {
      %8 = "addi32"(%i2, %i2) : (affineint, affineint) -> i32
      %9 = "addi32"(%8, %8) : (i32, i32) -> i32
    }
  }
  return
}

PiperOrigin-RevId: 209676220

lib/Parser/Parser.cpp

diff --git a/lib/Parser/Parser.cpp b/lib/Parser/Parser.cpp
index 174d6ca..0debe2d 100644
--- a/lib/Parser/Parser.cpp
+++ b/lib/Parser/Parser.cpp
@@ -2164,7 +2164,7 @@
 ParseResult MLFunctionParser::parseForStmt() {
   consumeToken(Token::kw_for);
 
-  // Parse induction variable
+  // Parse induction variable.
   if (getToken().isNot(Token::percent_identifier))
     return emitError("expected SSA identifier for the loop variable");
 
@@ -2175,7 +2175,7 @@
   if (parseToken(Token::equal, "expected '='"))
     return ParseFailure;
 
-  // Parse loop bounds
+  // Parse loop bounds.
   AffineConstantExpr *lowerBound = parseIntConstant();
   if (!lowerBound)
     return ParseFailure;
@@ -2187,12 +2187,13 @@
   if (!upperBound)
     return ParseFailure;
 
-  // Parse step
-  AffineConstantExpr *step = nullptr;
+  // Parse step.
+  int64_t step = 1;
   if (consumeIf(Token::kw_step)) {
-    step = parseIntConstant();
-    if (!step)
+    AffineConstantExpr *stepExpr = parseIntConstant();
+    if (!stepExpr)
       return ParseFailure;
+    step = stepExpr->getValue();
   }
 
   // Create for statement.