R600: Add checks for urem/srem by a constant

Make sure this uses the faster expansion using magic constants
to avoid the full division path.

llvm-svn: 226734

Author: arsenm

llvm/test/CodeGen/R600/srem.ll

@@ -1,4 +1,4 @@
-; RUN: llc -march=amdgcn -mcpu=SI < %s
+; RUN: llc -march=amdgcn -mcpu=SI < %s | FileCheck -check-prefix=SI -check-prefix=FUNC %s
 ; RUN: llc -march=r600 -mcpu=redwood < %s
 
 define void @srem_i32(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
@@ -17,6 +17,19 @@ define void @srem_i32_4(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
   ret void
 }
 
+; FUNC-LABEL: {{^}}srem_i32_7:
+; SI: v_mov_b32_e32 [[MAGIC:v[0-9]+]], 0x92492493
+; SI: v_mul_hi_i32 {{v[0-9]+}}, [[MAGIC]],
+; SI: v_mul_lo_i32
+; SI: v_sub_i32
+; SI: s_endpgm
+define void @srem_i32_7(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
+  %num = load i32 addrspace(1) * %in
+  %result = srem i32 %num, 7
+  store i32 %result, i32 addrspace(1)* %out
+  ret void
+}
+
 define void @srem_v2i32(<2 x i32> addrspace(1)* %out, <2 x i32> addrspace(1)* %in) {
   %den_ptr = getelementptr <2 x i32> addrspace(1)* %in, i32 1
   %num = load <2 x i32> addrspace(1) * %in

llvm/test/CodeGen/R600/urem.ll

@@ -17,6 +17,21 @@ define void @test_urem_i32(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
   ret void
 }
 
+; FUNC-LABEL: {{^}}test_urem_i32_7:
+; SI: v_mov_b32_e32 [[MAGIC:v[0-9]+]], 0x24924925
+; SI: v_mul_hi_u32 {{v[0-9]+}}, [[MAGIC]]
+; SI: v_subrev_i32
+; SI: v_mul_lo_i32
+; SI: v_sub_i32
+; SI: buffer_store_dword
+; SI: s_endpgm
+define void @test_urem_i32_7(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
+  %num = load i32 addrspace(1) * %in
+  %result = urem i32 %num, 7
+  store i32 %result, i32 addrspace(1)* %out
+  ret void
+}
+
 ; FUNC-LABEL: {{^}}test_urem_v2i32:
 ; SI: s_endpgm
 ; EG: CF_END