C-like emitter: Add parenthesis when combining relational and bitwise… (#6070)

* C-like emitter: Add redundant parentheses in several cases

This is required since the Dawn WGSL compiler requires parentheses even though precedence
rules could resolve order of operations.

This closes #6005.

* Fix tests/metal/byte-address-buffer

The output now includes parentheses around shift expressions appearing as operands in
bitwise expressions, so update the test accordingly.

* format code

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>
Co-authored-by: Yong He <yonghe@outlook.com>

1 files changed, 34 insertions, 144 deletions

diff --git a/source/slang/slang-emit-c-like.cpp b/source/slang/slang-emit-c-like.cpp
index d3a9359ff..eaf7ef028 100644
--- a/source/slang/slang-emit-c-like.cpp
+++ b/source/slang/slang-emit-c-like.cpp
@@ -706,6 +706,35 @@ void CLikeSourceEmitter::emitLivenessImpl(IRInst* inst)
 // Expressions
 //
 
+static bool isBitLogicalOrRelationalOrEquality(EPrecedence prec)
+{
+    switch (prec)
+    {
+    case EPrecedence::kEPrecedence_And_Left:
+    case EPrecedence::kEPrecedence_And_Right:
+    case EPrecedence::kEPrecedence_BitAnd_Left:
+    case EPrecedence::kEPrecedence_BitAnd_Right:
+    case EPrecedence::kEPrecedence_BitOr_Left:
+    case EPrecedence::kEPrecedence_BitOr_Right:
+    case EPrecedence::kEPrecedence_BitXor_Left:
+    case EPrecedence::kEPrecedence_BitXor_Right:
+    case EPrecedence::kEPrecedence_Or_Left:
+    case EPrecedence::kEPrecedence_Or_Right:
+    case EPrecedence::kEPrecedence_Relational_Left:
+    case EPrecedence::kEPrecedence_Relational_Right:
+    case EPrecedence::kEPrecedence_Shift_Left:
+    case EPrecedence::kEPrecedence_Shift_Right:
+    case EPrecedence::kEPrecedence_Equality_Left:
+    case EPrecedence::kEPrecedence_Equality_Right:
+        return true;
+
+    default:
+        break;
+    }
+
+    return false;
+}
+
 bool CLikeSourceEmitter::maybeEmitParens(EmitOpInfo& outerPrec, const EmitOpInfo& prec)
 {
     bool needParens = (prec.leftPrecedence <= outerPrec.leftPrecedence) ||
@@ -715,152 +744,13 @@ bool CLikeSourceEmitter::maybeEmitParens(EmitOpInfo& outerPrec, const EmitOpInfo
     // for common mistakes when parentheses are not used with certain combinations
     // of the operations. We emit parentheses to avoid the warnings.
     //
-    // a | b & c => a | (b & c)
-    if (prec.leftPrecedence == EPrecedence::kEPrecedence_BitAnd_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_BitOr_Right)
-    {
-        needParens = true;
-    }
-    // a & b | c => (a & b) | c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_BitAnd_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_BitOr_Left)
-    {
-        needParens = true;
-    }
-    // a << b + c => a << (b + c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Additive_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_Shift_Right)
-    {
-        needParens = true;
-    }
-    // a + b << c => (a + b) << c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Additive_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_Shift_Left)
-    {
-        needParens = true;
-    }
-    // a + b & c => (a + b) & c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Additive_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_BitAnd_Left)
-    {
-        needParens = true;
-    }
-    // a ^ b * c => (a ^ b) * c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_BitXor_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_Multiplicative_Left)
-    {
-        needParens = true;
-    }
-    // a ^ b + c => a ^ (b + c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Additive_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_BitXor_Right)
-    {
-        needParens = true;
-    }
-    // a + b ^ c => (a + b) ^ c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Additive_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_BitXor_Left)
-    {
-        needParens = true;
-    }
-    // a | b + c => a | (b + c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Additive_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_BitOr_Right)
-    {
-        needParens = true;
-    }
-    // a + b | c => (a + b) | c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Additive_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_BitOr_Left)
-    {
-        needParens = true;
-    }
-    // a ^ b * c => a ^ (b * c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Multiplicative_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_BitXor_Right)
-    {
-        needParens = true;
-    }
-    // a * b ^ c => (a * b) ^ c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Multiplicative_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_BitXor_Left)
-    {
-        needParens = true;
-    }
-    // a | b * c => a | (b * c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Multiplicative_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_BitOr_Right)
-    {
-        needParens = true;
-    }
-    // a * b | c => (a * b) | c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Multiplicative_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_BitOr_Left)
-    {
-        needParens = true;
-    }
-    // a & b * c => a & (b * c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Multiplicative_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_BitAnd_Right)
-    {
-        needParens = true;
-    }
-    // a * b & c => (a * b) & c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Multiplicative_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_BitAnd_Left)
-    {
-        needParens = true;
-    }
-    // a << b * c => a << (b * c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Multiplicative_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_Shift_Right)
-    {
-        needParens = true;
-    }
-    // a * b << c => (a * b) << c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Multiplicative_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_Shift_Left)
-    {
-        needParens = true;
-    }
-    // a != b == c => (a != b) == c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Equality_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_Equality_Left)
-    {
-        needParens = true;
-    }
-    // a == b < c => a == (b < c)
-    else if (
-        prec.leftPrecedence == EPrecedence::kEPrecedence_Relational_Left &&
-        outerPrec.leftPrecedence == EPrecedence::kEPrecedence_Equality_Right)
-    {
+
+    if (isBitLogicalOrRelationalOrEquality(prec.leftPrecedence) &&
+        (outerPrec.leftPrecedence > kEPrecedence_Assign_Left))
         needParens = true;
-    }
-    // a < b == c => (a < b) == c
-    else if (
-        prec.rightPrecedence == EPrecedence::kEPrecedence_Relational_Right &&
-        outerPrec.rightPrecedence == EPrecedence::kEPrecedence_Equality_Left)
-    {
+    if (isBitLogicalOrRelationalOrEquality(outerPrec.leftPrecedence) ||
+        isBitLogicalOrRelationalOrEquality(outerPrec.rightPrecedence))
         needParens = true;
-    }
 
     if (needParens)
     {