AMDGPU: Disallow exec as SMEM instruction operand

This is not in the list of valid inputs for the encoding.
When spilling, copies from exec can be folded directly
into the spill instruction which results in broken
stores.

This only fixes the operand constraints, more codegen
work is required to avoid emitting the invalid
spills.

This sort of breaks the dbg.value test. Because the
register class of the s_load_dwordx2 changes, there
is a copy to SReg_64, and the copy is the operand
of dbg_value. The copy is later dead, and removed
from the dbg_value.

llvm-svn: 288191

1 files changed, 9 insertions, 4 deletions

diff --git a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
index 9fac753..1a8c04b1 100644
--- a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
+++ b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
@@ -81,8 +81,9 @@ DECODE_OPERAND(VReg_96)
 DECODE_OPERAND(VReg_128)
 
 DECODE_OPERAND(SReg_32)
-DECODE_OPERAND(SReg_32_XM0)
+DECODE_OPERAND(SReg_32_XM0_XEXEC)
 DECODE_OPERAND(SReg_64)
+DECODE_OPERAND(SReg_64_XEXEC)
 DECODE_OPERAND(SReg_128)
 DECODE_OPERAND(SReg_256)
 DECODE_OPERAND(SReg_512)
@@ -277,13 +278,17 @@ MCOperand AMDGPUDisassembler::decodeOperand_SReg_32(unsigned Val) const {
   return decodeSrcOp(OPW32, Val);
 }
 
-MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XM0(unsigned Val) const {
-  // SReg_32_XM0 is SReg_32 without M0
+MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XM0_XEXEC(
+  unsigned Val) const {
+  // SReg_32_XM0 is SReg_32 without M0 or EXEC_LO/EXEC_HI
   return decodeOperand_SReg_32(Val);
 }
 
 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64(unsigned Val) const {
-  // see decodeOperand_SReg_32 comment
+  return decodeSrcOp(OPW64, Val);
+}
+
+MCOperand AMDGPUDisassembler::decodeOperand_SReg_64_XEXEC(unsigned Val) const {
   return decodeSrcOp(OPW64, Val);
 }