Address comments

This loses the benefit in the test

Author: arsenm

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -4426,15 +4426,10 @@ void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
 
       SDNodeFlags AddFlags;
 
-      // The successive addition of each offset (without adding the base
-      // address) does not wrap the pointer index type in a signed sense (add
-      // nsw).
-      if (NW.hasNoUnsignedSignedWrap())
-        AddFlags.setNoSignedWrap(true);
-
-      // The successive addition of each offset (without adding the base
-      // address) does not wrap the pointer index type in an unsigned sense (add
-      // nuw).
+      // The successive addition of the current address, truncated to the
+      // pointer index type and interpreted as an unsigned number, and each
+      // offset, also interpreted as an unsigned number, does not wrap the
+      // pointer index type (add nuw).
       if (NW.hasNoUnsignedWrap())
         AddFlags.setNoUnsignedWrap(true);
 

llvm/test/CodeGen/AMDGPU/gep-flags-stack-offsets.ll

@@ -118,7 +118,8 @@ define void @gep_inbounds_nuw_alloca(i32 %idx, i32 %val) #0 {
 ; GFX8-NEXT:    v_lshlrev_b32_e32 v0, 2, v0
 ; GFX8-NEXT:    v_lshrrev_b32_e64 v2, 6, s32
 ; GFX8-NEXT:    v_add_u32_e32 v0, vcc, v2, v0
-; GFX8-NEXT:    buffer_store_dword v1, v0, s[0:3], 0 offen offset:16
+; GFX8-NEXT:    v_add_u32_e32 v0, vcc, 16, v0
+; GFX8-NEXT:    buffer_store_dword v1, v0, s[0:3], 0 offen
 ; GFX8-NEXT:    s_waitcnt vmcnt(0)
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;
@@ -144,7 +145,8 @@ define void @gep_nusw_nuw_alloca(i32 %idx, i32 %val) #0 {
 ; GFX8-NEXT:    v_lshlrev_b32_e32 v0, 2, v0
 ; GFX8-NEXT:    v_lshrrev_b32_e64 v2, 6, s32
 ; GFX8-NEXT:    v_add_u32_e32 v0, vcc, v2, v0
-; GFX8-NEXT:    buffer_store_dword v1, v0, s[0:3], 0 offen offset:16
+; GFX8-NEXT:    v_add_u32_e32 v0, vcc, 16, v0
+; GFX8-NEXT:    buffer_store_dword v1, v0, s[0:3], 0 offen
 ; GFX8-NEXT:    s_waitcnt vmcnt(0)
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;