[llvm-commits] [llvm] r153770 - in /llvm/trunk: lib/Target/ARM/AsmParser/ARMAsmParser.cpp test/MC/ARM/basic-thumb2-instructions.s

[Jim Grosbach]

Author: grosbach
Date: Fri Mar 30 14:59:02 2012
New Revision: 153770

URL: http://llvm.org/viewvc/llvm-project?rev=153770&view=rev
Log:
ARM assembler should prefer non-aliases encoding of cmp.

When an immediate is both a value [t2_]so_imm and a [t2_]so_imm_neg,
we want to use the non-negated form to make sure we prefer the normal
encoding, not the aliased encoding via the negation of, e.g., 'cmp.w'.

Modified:
    llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
    llvm/trunk/test/MC/ARM/basic-thumb2-instructions.s

Modified: llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp?rev=153770&r1=153769&r2=153770&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp Fri Mar 30 14:59:02 2012
@@ -782,8 +782,9 @@
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
     if (!CE) return false;
     int64_t Value = CE->getValue();
-    // Negation must be representable as an so_imm and be non-zero.
-    return Value && ARM_AM::getSOImmVal(-Value) != -1;
+    // Only use this when not representable as a plain so_imm.
+    return ARM_AM::getSOImmVal(Value) == -1 &&
+      ARM_AM::getSOImmVal(-Value) != -1;
   }
   bool isT2SOImm() const {
     if (!isImm()) return false;
@@ -804,8 +805,9 @@
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
     if (!CE) return false;
     int64_t Value = CE->getValue();
-    // Negation must be representable as a t2_so_imm and be non-zero.
-    return Value && ARM_AM::getT2SOImmVal(-Value) != -1;
+    // Only use this when not representable as a plain so_imm.
+    return ARM_AM::getT2SOImmVal(Value) == -1 &&
+      ARM_AM::getT2SOImmVal(-Value) != -1;
   }
   bool isSetEndImm() const {
     if (!isImm()) return false;

Modified: llvm/trunk/test/MC/ARM/basic-thumb2-instructions.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/basic-thumb2-instructions.s?rev=153770&r1=153769&r2=153770&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/basic-thumb2-instructions.s (original)
+++ llvm/trunk/test/MC/ARM/basic-thumb2-instructions.s Fri Mar 30 14:59:02 2012
@@ -372,7 +372,8 @@
         cmp sp, r6, lsr #1
         cmp r2, r5, asr #24
         cmp r1, r4, ror #15
-        cmp r0, #-2
+        cmp r2, #-2
+        cmp r9, #1
 
 @ CHECK: cmp.w	r5, #65280              @ encoding: [0xb5,0xf5,0x7f,0x4f]
 @ CHECK: cmp.w	r4, r12                 @ encoding: [0xb4,0xeb,0x0c,0x0f]
@@ -381,7 +382,9 @@
 @ CHECK: cmp.w	sp, r6, lsr #1          @ encoding: [0xbd,0xeb,0x56,0x0f]
 @ CHECK: cmp.w	r2, r5, asr #24         @ encoding: [0xb2,0xeb,0x25,0x6f]
 @ CHECK: cmp.w	r1, r4, ror #15         @ encoding: [0xb1,0xeb,0xf4,0x3f]
-@ CHECK: cmn.w	r0, #2                  @ encoding: [0x10,0xf1,0x02,0x0f]
+@ CHECK: cmn.w	r2, #2                  @ encoding: [0x12,0xf1,0x02,0x0f]
+@ CHECK: cmp.w	r9, #1                  @ encoding: [0xb9,0xf1,0x01,0x0f]
+
 
 @------------------------------------------------------------------------------
 @ DBG