Index: llvm/lib/Target/AMDGPU/GCNSubtarget.h
===================================================================
--- llvm/lib/Target/AMDGPU/GCNSubtarget.h
+++ llvm/lib/Target/AMDGPU/GCNSubtarget.h
@@ -1307,7 +1307,9 @@
   createFillMFMAShadowMutation(const TargetInstrInfo *TII) const;
 
   bool isWave32() const {
-    return getWavefrontSize() == 32;
+    return (getGeneration() >= AMDGPUSubtarget::GFX10) &&
+           hasFeature(AMDGPU::FeatureWavefrontSize32) &&
+           (getWavefrontSize() == 32);
   }
 
   bool isWave64() const {
Index: llvm/test/CodeGen/AMDGPU/saveexec-xor-optimize-wave32.mir
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AMDGPU/saveexec-xor-optimize-wave32.mir
@@ -0,0 +1,23 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 2
+# RUN: llc -march=amdgcn -mcpu=gfx1010 -mattr=+wavefrontsize32 -run-pass=si-optimize-exec-masking -verify-machineinstrs %s -o - | FileCheck --check-prefixes=GFX10 %s
+# RUN: llc -march=amdgcn -mcpu=gfx90a -mattr=+wavefrontsize32 -run-pass=si-optimize-exec-masking -verify-machineinstrs %s -o - | FileCheck --check-prefixes=GFX9 %s
+
+---
+
+name: s_or_saveexec_xor_combine_b32
+tracksRegLiveness: true
+body: |
+  bb.0:
+    liveins: $sgpr0
+    ; GFX10-LABEL: name: s_or_saveexec_xor_combine_b32
+    ; GFX10: liveins: $sgpr0
+    ; GFX10-NEXT: {{  $}}
+    ; GFX10-NEXT: $sgpr0 = S_ANDN2_SAVEEXEC_B32 $sgpr0, implicit-def $exec, implicit-def $scc, implicit $exec
+    ; GFX9-LABEL: name: s_or_saveexec_xor_combine_b32
+    ; GFX9: liveins: $sgpr0
+    ; GFX9-NEXT: {{  $}}
+    ; GFX9-NEXT: renamable $sgpr0 = S_OR_SAVEEXEC_B32 killed renamable $sgpr0, implicit-def $exec, implicit-def $scc, implicit $exec
+    ; GFX9-NEXT: $exec_lo = S_XOR_B32 $exec_lo, renamable $sgpr0, implicit-def $scc
+    renamable $sgpr0 = S_OR_SAVEEXEC_B32 killed renamable $sgpr0, implicit-def $exec, implicit-def $scc, implicit $exec
+    $exec_lo = S_XOR_B32 $exec_lo, renamable $sgpr0, implicit-def $scc
+...