commit 1d2868c081f6d523d4fe2d88fe321074e53f68e5
author Calin Juravle <calin@google.com> Tue Mar 17 18:42:26 2015 +0000
committer Gerrit Code Review <noreply-gerritcodereview@google.com> Tue Mar 17 18:42:26 2015 +0000
tree b1f0e65127e4a9ca87f4843490a1993dd250e148
parent 3533c45b3411ec9ca3e65d956d5789b6333a0a77
parent 8de00e3f5fcb99bfd7e4dc679ab7333549bec2c1

Merge "Make subs alter flags when rn is an immediate"

compiler/utils/arm/assembler_thumb2.cc

diff --git a/compiler/utils/arm/assembler_thumb2.cc b/compiler/utils/arm/assembler_thumb2.cc
index eb5b454..e8eb019 100644
--- a/compiler/utils/arm/assembler_thumb2.cc
+++ b/compiler/utils/arm/assembler_thumb2.cc
@@ -826,7 +826,9 @@
     // Check special cases.
     if ((opcode == SUB || opcode == ADD) && (so.GetImmediate() < (1u << 12))) {
       if (opcode == SUB) {
-        thumb_opcode = 5U /* 0b0101 */;
+        if (!set_cc) {
+          thumb_opcode = 5U /* 0b0101 */;
+        }
       } else {
         thumb_opcode = 0;
       }
@@ -836,13 +838,14 @@
       uint32_t imm3 = (imm >> 8) & 7U /* 0b111 */;
       uint32_t imm8 = imm & 0xff;
 
-      encoding = B31 | B30 | B29 | B28 | B25 |
-           thumb_opcode << 21 |
-           rn << 16 |
-           rd << 8 |
-           i << 26 |
-           imm3 << 12 |
-           imm8;
+      encoding = B31 | B30 | B29 | B28 |
+          (set_cc ? B20 : B25) |
+          thumb_opcode << 21 |
+          rn << 16 |
+          rd << 8 |
+          i << 26 |
+          imm3 << 12 |
+          imm8;
     } else {
       // Modified immediate.
       uint32_t imm = ModifiedImmediate(so.encodingThumb());
@@ -858,13 +861,13 @@
           imm;
     }
   } else if (so.IsRegister()) {
-     // Register (possibly shifted)
-     encoding = B31 | B30 | B29 | B27 | B25 |
-         thumb_opcode << 21 |
-         (set_cc ? 1 : 0) << 20 |
-         rn << 16 |
-         rd << 8 |
-         so.encodingThumb();
+    // Register (possibly shifted)
+    encoding = B31 | B30 | B29 | B27 | B25 |
+        thumb_opcode << 21 |
+        (set_cc ? 1 : 0) << 20 |
+        rn << 16 |
+        rd << 8 |
+        so.encodingThumb();
   }
   Emit32(encoding);
 }

compiler/utils/arm/assembler_thumb2_test.cc

diff --git a/compiler/utils/arm/assembler_thumb2_test.cc b/compiler/utils/arm/assembler_thumb2_test.cc
index ebea9d4..d802852 100644
--- a/compiler/utils/arm/assembler_thumb2_test.cc
+++ b/compiler/utils/arm/assembler_thumb2_test.cc
@@ -227,4 +227,14 @@
   DriverStr(expected, "abs");
 }
 
+TEST_F(AssemblerThumb2Test, sub) {
+  __ subs(arm::R1, arm::R0, arm::ShifterOperand(42));
+  __ sub(arm::R1, arm::R0, arm::ShifterOperand(42));
+
+  const char* expected =
+      "subs r1, r0, #42\n"
+      "subw r1, r0, #42\n";
+  DriverStr(expected, "sub");
+}
+
 }  // namespace art