Feedback, change mcexpr from logical to bitwise or, documentation on mcexpr in AMDGPUUsage

Author: JanekvO

llvm/docs/AMDGPUUsage.rst

@@ -1534,6 +1534,24 @@ The AMDGPU backend supports the following calling conventions:
 
      =============================== ==========================================================
 
+AMDGPU MCExpr
+-------------
+
+As part of the AMDGPU MC layer, AMDGPU provides the following target specific
+``MCExpr``\s.
+
+  .. table:: AMDGPU MCExpr types:
+     :name: amdgpu-mcexpr-table
+
+     =================== ======================================================================
+     AMDGPU MCExpr       Description
+     =================== ======================================================================
+     ``max(arg, ...)``   Variadic operation that returns maximum value of all its arguments.
+
+     ``or(arg, ...)``    Variadic operation that returns the bitwise-or result of all its
+                         arguments.
+
+     =================== ======================================================================
 
 .. _amdgpu-elf-code-object:
 

llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.cpp

@@ -57,7 +57,7 @@ static int64_t op(AMDGPUVariadicMCExpr::VariadicKind Kind, int64_t Arg1,
   case AMDGPUVariadicMCExpr::AGVK_Max:
     return std::max(Arg1, Arg2);
   case AMDGPUVariadicMCExpr::AGVK_Or:
-    return Arg1 || Arg2;
+    return Arg1 | Arg2;
   }
 }
 

llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.h

@@ -19,7 +19,7 @@ namespace llvm {
 ///
 /// Takes in a minimum of 1 argument to be used with an operation. The supported
 /// operations are:
-///   - (logic) or
+///   - (bitwise) or
 ///   - max
 ///
 /// \note If the 'or'/'max' operations are provided only a single argument, the

llvm/test/MC/AMDGPU/mcexpr_amd.s

@@ -29,16 +29,16 @@
 // OBJDUMP-NEXT: 8000000000000000 l       *ABS*  0000000000000000 max_expr_one_min
 // OBJDUMP-NEXT: 0000000000000003 l       *ABS*  0000000000000000 max_expr_two_min
 // OBJDUMP-NEXT: 0000000000989680 l       *ABS*  0000000000000000 max_expr_three_min
-// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_expression_all
-// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_expression_two
+// OBJDUMP-NEXT: 0000000000000007 l       *ABS*  0000000000000000 or_expression_all
+// OBJDUMP-NEXT: 0000000000000003 l       *ABS*  0000000000000000 or_expression_two
 // OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_expression_one
-// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_literals
+// OBJDUMP-NEXT: 000000000000000f l       *ABS*  0000000000000000 or_literals
 // OBJDUMP-NEXT: 0000000000000000 l       *ABS*  0000000000000000 or_false
-// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_with_or_sym
+// OBJDUMP-NEXT: 00000000000000ff l       *ABS*  0000000000000000 or_with_or_sym
 // OBJDUMP-NEXT: 00000000000000ff l       *ABS*  0000000000000000 or
-// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_with_subexpr
-// OBJDUMP-NEXT: 0000000000000002 l       *ABS*  0000000000000000 or_as_subexpr
-// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_recursive_subexpr
+// OBJDUMP-NEXT: 0000000000000003 l       *ABS*  0000000000000000 or_with_subexpr
+// OBJDUMP-NEXT: 0000000000000008 l       *ABS*  0000000000000000 or_as_subexpr
+// OBJDUMP-NEXT: 0000000000000007 l       *ABS*  0000000000000000 or_recursive_subexpr
 
 // ASM: .set zero, 0
 // ASM: .set one, 1
@@ -98,9 +98,9 @@
 .set max_expr_three_min, max(i64_min, three, 10000000)
 
 // ASM: .set or_expression_all, or(1, 2, five, 3, four)
-// ASM: .set or_expression_two, 1
+// ASM: .set or_expression_two, 3
 // ASM: .set or_expression_one, 1
-// ASM: .set or_literals, 1
+// ASM: .set or_literals, 15
 // ASM: .set or_false, 0
 // ASM: .set or_with_or_sym, or(or, 4, 3, 1, 2)
 
@@ -111,7 +111,7 @@
 .set or_false, or(zero, 0, (2-2), 5 > 6)
 .set or_with_or_sym, or(or, 4, 3, one, two)
 
-// ASM: .set or_with_subexpr, 1
+// ASM: .set or_with_subexpr, 3
 // ASM: .set or_as_subexpr, 1+(or(4, 3, five))
 // ASM: .set or_recursive_subexpr, or(or(1, four), 3, or_expression_all)