Change ARM VFP VLDM/VSTM instructions to use addressing mode #4, just like

all the other LDM/STM instructions.  This fixes asm printer crashes when
compiling with -O0.  I've changed one of the NEON tests (vst3.ll) to run
with -O0 to check this in the future.

Prior to this change VLDM/VSTM used addressing mode #5, but not really.
The offset field was used to hold a count of the number of registers being
loaded or stored, and the AM5 opcode field was expanded to specify the IA
or DB mode, instead of the standard ADD/SUB specifier.  Much of the backend
was not aware of these special cases.  The crashes occured when rewriting
a frameindex caused the AM5 offset field to be changed so that it did not
have a valid submode.  I don't know exactly what changed to expose this now.
Maybe we've never done much with -O0 and NEON.  Regardless, there's no longer
any reason to keep a count of the VLDM/VSTM registers, so we can use
addressing mode #4 and clean things up in a lot of places.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112322 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 19 deletions

diff --git a/lib/Target/ARM/ARMAddressingModes.h b/lib/Target/ARM/ARMAddressingModes.h
index 92a13f1..db48100 100644
--- a/lib/Target/ARM/ARMAddressingModes.h
+++ b/lib/Target/ARM/ARMAddressingModes.h
@@ -458,6 +458,7 @@ namespace ARM_AM {
   //    IB - Increment before
   //    DA - Decrement after
   //    DB - Decrement before
+  // For VFP instructions, only the IA and DB modes are valid.
 
   static inline AMSubMode getAM4SubMode(unsigned Mode) {
     return (AMSubMode)(Mode & 0x7);
@@ -477,14 +478,6 @@ namespace ARM_AM {
   //
   // The first operand is always a Reg.  The second operand encodes the
   // operation in bit 8 and the immediate in bits 0-7.
-  //
-  // This is also used for FP load/store multiple ops. The second operand
-  // encodes the number of registers (or 2 times the number of registers
-  // for DPR ops) in bits 0-7. In addition, bits 8-10 encode one of the
-  // following two sub-modes:
-  //
-  //    IA - Increment after
-  //    DB - Decrement before
 
   /// getAM5Opc - This function encodes the addrmode5 opc field.
   static inline unsigned getAM5Opc(AddrOpc Opc, unsigned char Offset) {
@@ -498,17 +491,6 @@ namespace ARM_AM {
     return ((AM5Opc >> 8) & 1) ? sub : add;
   }
 
-  /// getAM5Opc - This function encodes the addrmode5 opc field for VLDM and
-  /// VSTM instructions.
-  static inline unsigned getAM5Opc(AMSubMode SubMode, unsigned char Offset) {
-    assert((SubMode == ia || SubMode == db) &&
-           "Illegal addressing mode 5 sub-mode!");
-    return ((int)SubMode << 8) | Offset;
-  }
-  static inline AMSubMode getAM5SubMode(unsigned AM5Opc) {
-    return (AMSubMode)((AM5Opc >> 8) & 0x7);
-  }
-
   //===--------------------------------------------------------------------===//
   // Addressing Mode #6
   //===--------------------------------------------------------------------===//