Reorder commutative ops involving constant variables or XOR.

Previously, we would reorder `2 * x` into `x * 2` (since the latter can use an immediate op), but we would not have reordered `PI * x` because `PI` is a constant variable, not a Literal. We now detect those cases and rewrite as `x * PI` (allowing us to save an instruction via `mul_imm_float`). Also, we now apply commutative reordering to ^ and ^^, since the xor op now has an immediate-mode version. Change-Id: I1e1da2d31e8df48ec4c57c544dcc5bca7944f25e Reviewed-on: https://skia-review.googlesource.com/c/skia/+/684099 Commit-Queue: Brian Osman <[email protected]> Auto-Submit: John Stiles <[email protected]> Reviewed-by: Brian Osman <[email protected]>
armansito · Apr 27, 2023 · 0102755 · 0102755
1 parent a21a30c
commit 0102755
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Showing 3 changed files with 12 additions and 11 deletions.
diff --git a/src/sksl/codegen/SkSLRasterPipelineCodeGenerator.cpp b/src/sksl/codegen/SkSLRasterPipelineCodeGenerator.cpp
@@ -2261,11 +2261,15 @@ bool Generator::pushBinaryExpression(const Expression& left, Operator op, const
         // Builder more opportunities to use immediate-mode ops.
         case OperatorKind::PLUS:
         case OperatorKind::STAR:
-            if (left.is<Literal>() && !right.is<Literal>()) {
+        case OperatorKind::BITWISEXOR:
+        case OperatorKind::LOGICALXOR: {
+            double unused;
+            if (ConstantFolder::GetConstantValue(left, &unused) &&
+                !ConstantFolder::GetConstantValue(right, &unused)) {
                 return this->pushBinaryExpression(right, op, left);
             }
             break;
-
+        }
         // Emit comma expressions.
         case OperatorKind::COMMA:
             if (Analysis::HasSideEffects(left)) {

diff --git a/tests/sksl/folding/ArrayFolding.skrp b/tests/sksl/folding/ArrayFolding.skrp
@@ -30,16 +30,14 @@ copy_slot_unmasked             _7_two = $13
 copy_constant                  $14 = 0x00000003 (4.203895e-45)
 copy_slot_unmasked             $0 = $14
 copy_slot_unmasked             _13_noFlatten2 = $0
-copy_constant                  $0 = 0x00000001 (1.401298e-45)
-copy_slot_unmasked             $1 = _11_noFlatten0
-cmpeq_int                      $0 = equal($0, $1)
+copy_slot_unmasked             $0 = _11_noFlatten0
+cmpeq_imm_int                  $0 = equal($0, 0x00000001)
 copy_slot_unmasked             $1 = _9_flatten1
 copy_slot_unmasked             $2 = _12_noFlatten1
 cmpeq_int                      $1 = equal($1, $2)
 bitwise_and_int                $0 &= $1
-copy_constant                  $1 = 0x00000003 (4.203895e-45)
-copy_slot_unmasked             $2 = _13_noFlatten2
-cmpeq_int                      $1 = equal($1, $2)
+copy_slot_unmasked             $1 = _13_noFlatten2
+cmpeq_imm_int                  $1 = equal($1, 0x00000003)
 bitwise_and_int                $0 &= $1
 swizzle_4                      $0..3 = ($0..3).xxxx
 copy_4_uniforms                $4..7 = colorRed

diff --git a/tests/sksl/folding/ShortCircuitBoolFolding.skrp b/tests/sksl/folding/ShortCircuitBoolFolding.skrp
@@ -19,9 +19,8 @@ copy_slot_masked               _2_bad = Mask($2)
 load_condition_mask            CondMask = $0
 add_imm_int                    _1_ok += 0x00000001
 store_condition_mask           $0 = CondMask
-copy_constant                  $1 = 0xFFFFFFFF
-copy_slot_unmasked             $2 = _0_expr
-bitwise_xor_int                $1 ^= $2
+copy_slot_unmasked             $1 = _0_expr
+bitwise_xor_imm_int            $1 ^= 0xFFFFFFFF
 merge_condition_mask           CondMask = $0 & $1
 copy_slot_unmasked             $2 = _2_bad
 add_imm_int                    $2 += 0x00000001