AMDGPU: Correct DS implementation of areLoadsFromSameBasePtr

This was checking the wrong operands for the base register and the
offsets. The indexes are shifted by the number of output registers
from the machine instruction definition, and the chain is moved to the
end.

llvm-svn: 355722

2 files changed, 6 insertions, 6 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
index 8abf91b8ae2..db622f39933 100644
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -167,7 +167,7 @@ bool SIInstrInfo::areLoadsFromSameBasePtr(SDNode *Load0, SDNode *Load1,
       return false;
 
     // Check base reg.
-    if (Load0->getOperand(1) != Load1->getOperand(1))
+    if (Load0->getOperand(0) != Load1->getOperand(0))
       return false;
 
     // Check chain.
@@ -181,8 +181,8 @@ bool SIInstrInfo::areLoadsFromSameBasePtr(SDNode *Load0, SDNode *Load1,
         AMDGPU::getNamedOperandIdx(Opc1, AMDGPU::OpName::data1) != -1)
       return false;
 
-    Offset0 = cast<ConstantSDNode>(Load0->getOperand(2))->getZExtValue();
-    Offset1 = cast<ConstantSDNode>(Load1->getOperand(2))->getZExtValue();
+    Offset0 = cast<ConstantSDNode>(Load0->getOperand(1))->getZExtValue();
+    Offset1 = cast<ConstantSDNode>(Load1->getOperand(1))->getZExtValue();
     return true;
   }
 
@@ -232,7 +232,7 @@ bool SIInstrInfo::areLoadsFromSameBasePtr(SDNode *Load0, SDNode *Load1,
       return false;
 
     // getNamedOperandIdx returns the index for MachineInstrs.  Since they
-    // inlcude the output in the operand list, but SDNodes don't, we need to
+    // include the output in the operand list, but SDNodes don't, we need to
     // subtract the index by one.
     --OffIdx0;
     --OffIdx1;
diff --git a/llvm/test/CodeGen/AMDGPU/ds-combine-with-dependence.ll b/llvm/test/CodeGen/AMDGPU/ds-combine-with-dependence.ll
index 06fa048124a..ba7c0f3983c 100644
--- a/llvm/test/CodeGen/AMDGPU/ds-combine-with-dependence.ll
+++ b/llvm/test/CodeGen/AMDGPU/ds-combine-with-dependence.ll
@@ -6,8 +6,8 @@
 
 ; GCN-LABEL: {{^}}ds_combine_nodep
 
-; GCN:      ds_write2_b32 v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}} offset0:26 offset1:27
-; GCN-NEXT: ds_read2_b32 v{{\[[0-9]+:[0-9]+\]}}, v{{[0-9]+}} offset0:7 offset1:8
+; GCN: ds_read2_b32 v{{\[[0-9]+:[0-9]+\]}}, v{{[0-9]+}} offset0:7 offset1:8
+; GCN-NEXT: ds_write2_b32 v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}} offset0:26 offset1:27
 define amdgpu_kernel void @ds_combine_nodep(float addrspace(1)* %out, float addrspace(3)* %inptr) {
 
   %base = bitcast float addrspace(3)* %inptr to i8 addrspace(3)*