[llvm] [AMDGPU] V_SET_INACTIVE optimizations (PR #98864)

[Jay Foad via llvm-commits]

================
@@ -12,97 +12,204 @@ define amdgpu_cs_chain void @set_inactive_chain_arg(ptr addrspace(1) %out, i32 %
 ; GFX11-LABEL: set_inactive_chain_arg:
 ; GFX11:       ; %bb.0:
 ; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX11-NEXT:    v_mov_b32_e32 v0, v11
-; GFX11-NEXT:    s_not_b32 exec_lo, exec_lo
+; GFX11-NEXT:    s_or_saveexec_b32 s0, -1
 ; GFX11-NEXT:    v_mov_b32_e32 v0, v10
-; GFX11-NEXT:    s_not_b32 exec_lo, exec_lo
-; GFX11-NEXT:    global_store_b32 v[8:9], v0, off
+; GFX11-NEXT:    s_mov_b32 exec_lo, s0
+; GFX11-NEXT:    s_or_saveexec_b32 s0, -1
----------------
jayfoad wrote:

This pair of instructions could be removed.

https://github.com/llvm/llvm-project/pull/98864