Correct compatibility with the GNU Assembler's handling of comparison ops

GAS returns -1 for a comparison operator if the result is true and 0 if false.

  https://www.sourceware.org/binutils/docs-2.12/as.info/Infix-Ops.html#Infix%20Ops

llvm-svn: 332215

4 files changed, 41 insertions, 13 deletions

diff --git a/llvm/lib/MC/MCExpr.cpp b/llvm/lib/MC/MCExpr.cpp
index f9b88895245..831c692fb2e 100644
--- a/llvm/lib/MC/MCExpr.cpp
+++ b/llvm/lib/MC/MCExpr.cpp
@@ -74,7 +74,10 @@ void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const {
     case MCUnaryExpr::Not:   OS << '~'; break;
     case MCUnaryExpr::Plus:  OS << '+'; break;
     }
+    bool Binary = UE.getSubExpr()->getKind() == MCExpr::Binary;
+    if (Binary) OS << "(";
     UE.getSubExpr()->print(OS, MAI);
+    if (Binary) OS << ")";
     return;
   }
 
@@ -756,7 +759,8 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
     // Apple as.
     int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
     int64_t Result = 0;
-    switch (ABE->getOpcode()) {
+    auto Op = ABE->getOpcode();
+    switch (Op) {
     case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
     case MCBinaryExpr::Add:  Result = LHS + RHS; break;
     case MCBinaryExpr::And:  Result = LHS & RHS; break;
@@ -791,7 +795,21 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
     case MCBinaryExpr::Xor:  Result = LHS ^ RHS; break;
     }
 
-    Res = MCValue::get(Result);
+    switch (Op) {
+    default:
+      Res = MCValue::get(Result);
+      break;
+    case MCBinaryExpr::EQ:
+    case MCBinaryExpr::GT:
+    case MCBinaryExpr::GTE:
+    case MCBinaryExpr::LT:
+    case MCBinaryExpr::LTE:
+    case MCBinaryExpr::NE:
+      // A comparison operator returns a -1 if true and 0 if false.
+      Res = MCValue::get(Result ? -1 : 0);
+      break;
+    }
+
     return true;
   }
   }
diff --git a/llvm/test/MC/AsmParser/altmacro_string.s b/llvm/test/MC/AsmParser/altmacro_string.s
index 70012b2b852..ce024676b25 100644
--- a/llvm/test/MC/AsmParser/altmacro_string.s
+++ b/llvm/test/MC/AsmParser/altmacro_string.s
@@ -32,7 +32,7 @@ concat <simple>,<Check>,<0>
 # Test #3:
 # The altmacro cannot affect the regular less/greater behavior.
 
-# CHECK: addl $1, %eax
+# CHECK: addl $-1, %eax
 # CHECK: addl $0, %eax
 
 .macro fun3 arg1 arg2
diff --git a/llvm/test/MC/AsmParser/directive_space.s b/llvm/test/MC/AsmParser/directive_space.s
index eadc4fc6383..dc21a3b88e2 100644
--- a/llvm/test/MC/AsmParser/directive_space.s
+++ b/llvm/test/MC/AsmParser/directive_space.s
@@ -11,11 +11,21 @@ TEST1:
         .space 2, 3
 
 # CHECK: TEST2:
+# CHECK: .space	1,3
+TEST2:  
+        .space -(2 > 0), 3
+
+# CHECK: TEST3:
 # CHECK: .space 1
-TEST2:
+TEST3:
         .skip 1
 
-# CHECK: TEST3
+# CHECK: TEST4
 # CHECK: .space TEST0-TEST1
-TEST3:
-        .space TEST0 - TEST1
+TEST4:
+        .skip TEST0 - TEST1
+
+# CHECK: TEST5
+# CHECK: .space -((TEST0-TEST1)>0)
+TEST5:
+        .skip -((TEST0 - TEST1) > 0)
diff --git a/llvm/test/MC/AsmParser/exprs.s b/llvm/test/MC/AsmParser/exprs.s
index 1c3e284bcf7..d2e2334e836 100644
--- a/llvm/test/MC/AsmParser/exprs.s
+++ b/llvm/test/MC/AsmParser/exprs.s
@@ -21,12 +21,12 @@ k:
         check_expr 1 & 3, 1
         check_expr 4 / 2, 2
         check_expr 4 / -2, -2
-        check_expr 1 == 1, 1
+        check_expr 1 == 1, -1
         check_expr 1 == 0, 0
-        check_expr 1 > 0, 1
-        check_expr 1 >= 1, 1
-        check_expr 1 < 2, 1
-        check_expr 1 <= 1, 1
+        check_expr 1 > 0, -1
+        check_expr 1 >= 1, -1
+        check_expr 1 < 2, -1
+        check_expr 1 <= 1, -1
         check_expr 4 % 3, 1
         check_expr 2 * 2, 4
         check_expr 2 != 2, 0
@@ -43,7 +43,7 @@ k:
         check_expr 1 || 2, 1
         check_expr 0 || 1, 1
         check_expr 0 || 0, 0
-        check_expr 1 + 2 < 3 + 4, 1
+        check_expr 1 + 2 < 3 + 4, -1
         check_expr 1 << 8 - 1, 128
         check_expr 3 * 9 - 2 * 9 + 1, 10