R600/SI: Remove i1 pseudo VALU ops

Select i1 logical ops directly to 64-bit SALU instructions.
Vector i1 values are always really in SGPRs, with each
bit for each item in the wave. This saves about 4 instructions
when and/or/xoring any condition, and also helps write conditions
that need to be passed in vcc.

This should work correctly now that the SGPR live range
fixing pass works. More work is needed to eliminate the VReg_1
pseudo regclass and possibly the entire SILowerI1Copies pass.

llvm-svn: 223206

1 files changed, 41 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/R600/sgpr-control-flow.ll b/llvm/test/CodeGen/R600/sgpr-control-flow.ll
index d8b8dffa7fa..667c4ea3a4e 100644
--- a/llvm/test/CodeGen/R600/sgpr-control-flow.ll
+++ b/llvm/test/CodeGen/R600/sgpr-control-flow.ll
@@ -59,6 +59,47 @@ endif:
   ret void
 }
 
+; FIXME: Should write to different SGPR pairs instead of copying to
+; VALU for i1 phi.
+
+; SI-LABEL: {{^}}sgpr_if_else_valu_cmp_phi_br:
+; SI: buffer_load_dword [[AVAL:v[0-9]+]]
+; SI: v_cmp_lt_i32_e64 [[CMP_IF:s\[[0-9]+:[0-9]+\]]], [[AVAL]], 0
+; SI: v_cndmask_b32_e64 [[V_CMP:v[0-9]+]], 0, -1, [[CMP_IF]]
+
+; SI: BB2_1:
+; SI: buffer_load_dword [[AVAL:v[0-9]+]]
+; SI: v_cmp_eq_i32_e64 [[CMP_ELSE:s\[[0-9]+:[0-9]+\]]], [[AVAL]], 0
+; SI: v_cndmask_b32_e64 [[V_CMP]], 0, -1, [[CMP_ELSE]]
+
+; SI: v_cmp_ne_i32_e64 [[CMP_CMP:s\[[0-9]+:[0-9]+\]]], [[V_CMP]], 0
+; SI: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, -1, [[CMP_CMP]]
+; SI: buffer_store_dword [[RESULT]]
+define void @sgpr_if_else_valu_cmp_phi_br(i32 addrspace(1)* %out, i32 addrspace(1)* %a, i32 addrspace(1)* %b) {
+entry:
+  %tid = call i32 @llvm.r600.read.tidig.x() #0
+  %tmp1 = icmp eq i32 %tid, 0
+  br i1 %tmp1, label %if, label %else
+
+if:
+  %gep.if = getelementptr i32 addrspace(1)* %a, i32 %tid
+  %a.val = load i32 addrspace(1)* %gep.if
+  %cmp.if = icmp eq i32 %a.val, 0
+  br label %endif
+
+else:
+  %gep.else = getelementptr i32 addrspace(1)* %b, i32 %tid
+  %b.val = load i32 addrspace(1)* %gep.else
+  %cmp.else = icmp slt i32 %b.val, 0
+  br label %endif
+
+endif:
+  %tmp4 = phi i1 [%cmp.if, %if], [%cmp.else, %else]
+  %ext = sext i1 %tmp4 to i32
+  store i32 %ext, i32 addrspace(1)* %out
+  ret void
+}
+
 declare i32 @llvm.r600.read.tidig.x() #0
 
 attributes #0 = { readnone }