summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAli Saidi <Ali.Saidi@ARM.com>2010-11-15 14:04:05 -0600
committerAli Saidi <Ali.Saidi@ARM.com>2010-11-15 14:04:05 -0600
commit5f59e195d61c9144c817aab4a9179036adad6c9c (patch)
tree276229c98c76f736f262448880d3d504b9c20feb
parent371110fb0a8b5c687682c8ce1e1445eee1d3a7bc (diff)
downloadgem5-5f59e195d61c9144c817aab4a9179036adad6c9c.tar.xz
ARM: Add comment about the organization of the IT state register
-rw-r--r--src/arch/arm/miscregs.hh6
1 files changed, 6 insertions, 0 deletions
diff --git a/src/arch/arm/miscregs.hh b/src/arch/arm/miscregs.hh
index aa3f47419..2bb1cdb15 100644
--- a/src/arch/arm/miscregs.hh
+++ b/src/arch/arm/miscregs.hh
@@ -262,6 +262,12 @@ namespace ArmISA
EndBitUnion(CPSR)
BitUnion8(ITSTATE)
+ /* Note that the split (cond, mask) below is not as in ARM ARM.
+ * But it is more convenient for simulation. The condition
+ * is always the concatenation of the top 3 bits and the next bit,
+ * which applies when one of the bottom 4 bits is set.
+ * Refer to predecoder.cc for the use case.
+ */
Bitfield<7, 4> cond;
Bitfield<3, 0> mask;
// Bitfields for moving to/from CPSR