Enable (sext x) == C --> x == (trunc C) combine

[arsenm]

Summary

Extend the existing code which handles this for zext. This makes this more useful for targets with ZeroOrNegativeOne BooleanContent and obsoletes a custom combine SI uses for i1 setcc (sext(i1), 0, setne) since the constant will now be shrunk to i1.

[arsenm]

ping

[arsenm]

r224691

lib/CodeGen/SelectionDAG/TargetLowering.cpp

     }
 
     // (zext x) == C --> x == (trunc C)
-    if (DCI.isBeforeLegalize() && N0->hasOneUse() &&
-        (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
+    // (sext x) == C --> x == (trunc C)
+    if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
+        DCI.isBeforeLegalize() && N0->hasOneUse()) {
       unsigned MinBits = N0.getValueSizeInBits();
-      SDValue PreZExt;
+      SDValue PreExt;
+      bool Signed = false;
       if (N0->getOpcode() == ISD::ZERO_EXTEND) {
         // ZExt
         MinBits = N0->getOperand(0).getValueSizeInBits();
-        PreZExt = N0->getOperand(0);
+        PreExt = N0->getOperand(0);
       } else if (N0->getOpcode() == ISD::AND) {
         // DAGCombine turns costly ZExts into ANDs
         if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0->getOperand(1)))
           if ((C->getAPIntValue()+1).isPowerOf2()) {
             MinBits = C->getAPIntValue().countTrailingOnes();
-            PreZExt = N0->getOperand(0);
+            PreExt = N0->getOperand(0);
           }
+      } else if (N0->getOpcode() == ISD::SIGN_EXTEND) {
+        // SExt
+        MinBits = N0->getOperand(0).getValueSizeInBits();
+        PreExt = N0->getOperand(0);
+        Signed = true;
       } else if (LoadSDNode *LN0 = dyn_cast<LoadSDNode>(N0)) {
-        // ZEXTLOAD
+        // ZEXTLOAD / SEXTLOAD
         if (LN0->getExtensionType() == ISD::ZEXTLOAD) {
           MinBits = LN0->getMemoryVT().getSizeInBits();
-          PreZExt = N0;
+          PreExt = N0;
+        } else if (LN0->getExtensionType() == ISD::SEXTLOAD) {
+          Signed = true;
+          MinBits = LN0->getMemoryVT().getSizeInBits();
+          PreExt = N0;
         }
       }
 
+      // Figure out how many bits we need to preserve this constant.
+      unsigned ReqdBits = Signed ?
+        C1.getBitWidth() - C1.getNumSignBits() + 1 :
+        C1.getActiveBits();
+
       // Make sure we're not losing bits from the constant.
       if (MinBits > 0 &&
-          MinBits < C1.getBitWidth() && MinBits >= C1.getActiveBits()) {
+          MinBits < C1.getBitWidth() &&
+          MinBits >= ReqdBits) {
         EVT MinVT = EVT::getIntegerVT(*DAG.getContext(), MinBits);
         if (isTypeDesirableForOp(ISD::SETCC, MinVT)) {
           // Will get folded away.
-          SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MinVT, PreZExt);
+          SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MinVT, PreExt);
           SDValue C = DAG.getConstant(C1.trunc(MinBits), MinVT);
           return DAG.getSetCC(dl, VT, Trunc, C, Cond);
         }

lib/Target/R600/SIISelLowering.cpp

                                             DAGCombinerInfo &DCI) const {
   SelectionDAG &DAG = DCI.DAG;
   SDLoc DL(N);
-  EVT VT = N->getValueType(0);
 
   switch (N->getOpcode()) {
-    default: return AMDGPUTargetLowering::PerformDAGCombine(N, DCI);
-    case ISD::SETCC: {
-      SDValue Arg0 = N->getOperand(0);
-      SDValue Arg1 = N->getOperand(1);
-      SDValue CC = N->getOperand(2);
-      ConstantSDNode * C = nullptr;
-      ISD::CondCode CCOp = dyn_cast<CondCodeSDNode>(CC)->get();
-
-      // i1 setcc (sext(i1), 0, setne) -> i1 setcc(i1, 0, setne)
-      if (VT == MVT::i1
-          && Arg0.getOpcode() == ISD::SIGN_EXTEND
-          && Arg0.getOperand(0).getValueType() == MVT::i1
-          && (C = dyn_cast<ConstantSDNode>(Arg1))
-          && C->isNullValue()
-          && CCOp == ISD::SETNE) {
-        return SimplifySetCC(VT, Arg0.getOperand(0),
-                             DAG.getConstant(0, MVT::i1), CCOp, true, DCI, DL);
-      }
-      break;
-    }
+  default:
+    return AMDGPUTargetLowering::PerformDAGCombine(N, DCI);
   case ISD::FMAXNUM: // TODO: What about fmax_legacy?
   case ISD::FMINNUM:
   case AMDGPUISD::SMAX:

test/CodeGen/R600/setcc-opt.ll

 ; RUN: llc -march=r600 -mcpu=SI -verify-machineinstrs < %s | FileCheck -check-prefix=SI -check-prefix=FUNC %s
+; RUN: llc -march=r600 -mcpu=cypress -verify-machineinstrs < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
 
-; SI-LABEL: {{^}}sext_bool_icmp_ne:
-; SI: v_cmp_ne_i32
-; SI-NEXT: v_cndmask_b32
-; SI-NOT: v_cmp_ne_i32
-; SI-NOT: v_cndmask_b32
-; SI: s_endpgm
-define void @sext_bool_icmp_ne(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+; FUNC-LABEL: {{^}}sext_bool_icmp_eq_0:
+; SI-NOT: v_cmp
+; SI: v_cmp_ne_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, vcc
+; SI-NEXT:buffer_store_byte [[RESULT]]
+; SI-NEXT: s_endpgm
+
+; EG: SETNE_INT * [[CMP:T[0-9]+]].[[CMPCHAN:[XYZW]]], KC0[2].Z, KC0[2].W
+; EG: AND_INT T{{[0-9]+.[XYZW]}}, PS, 1
+define void @sext_bool_icmp_eq_0(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp eq i32 %a, %b
+  %ext = sext i1 %icmp0 to i32
+  %icmp1 = icmp eq i32 %ext, 0
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}sext_bool_icmp_ne_0:
+; SI-NOT: v_cmp
+; SI: v_cmp_ne_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, vcc
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI-NEXT: s_endpgm
+
+; EG: SETNE_INT * [[CMP:T[0-9]+]].[[CMPCHAN:[XYZW]]], KC0[2].Z, KC0[2].W
+; EG: AND_INT T{{[0-9]+.[XYZW]}}, PS, 1
+define void @sext_bool_icmp_ne_0(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp ne i32 %a, %b
+  %ext = sext i1 %icmp0 to i32
+  %icmp1 = icmp ne i32 %ext, 0
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; This really folds away to false
+; FUNC-LABEL: {{^}}sext_bool_icmp_eq_1:
+; SI: v_cmp_eq_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[TMP:v[0-9]+]], 0, -1, vcc
+; SI-NEXT: v_cmp_eq_i32_e64 {{s\[[0-9]+:[0-9]+\]}}, [[TMP]], 1{{$}}
+; SI-NEXT: v_cndmask_b32_e64 [[TMP:v[0-9]+]], 0, 1,
+; SI-NEXT: buffer_store_byte [[TMP]]
+; SI-NEXT: s_endpgm
+define void @sext_bool_icmp_eq_1(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp eq i32 %a, %b
+  %ext = sext i1 %icmp0 to i32
+  %icmp1 = icmp eq i32 %ext, 1
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; This really folds away to true
+; FUNC-LABEL: {{^}}sext_bool_icmp_ne_1:
+; SI: v_cmp_ne_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[TMP:v[0-9]+]], 0, -1, vcc
+; SI-NEXT: v_cmp_ne_i32_e64 {{s\[[0-9]+:[0-9]+\]}}, [[TMP]], 1{{$}}
+; SI-NEXT: v_cndmask_b32_e64 [[TMP:v[0-9]+]], 0, 1,
+; SI-NEXT: buffer_store_byte [[TMP]]
+; SI-NEXT: s_endpgm
+define void @sext_bool_icmp_ne_1(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
   %icmp0 = icmp ne i32 %a, %b
   %ext = sext i1 %icmp0 to i32
+  %icmp1 = icmp ne i32 %ext, 1
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zext_bool_icmp_eq_0:
+; SI-NOT: v_cmp
+; SI: v_cmp_ne_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, vcc
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI-NEXT: s_endpgm
+define void @zext_bool_icmp_eq_0(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp eq i32 %a, %b
+  %ext = zext i1 %icmp0 to i32
+  %icmp1 = icmp eq i32 %ext, 0
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zext_bool_icmp_ne_0:
+; SI-NOT: v_cmp
+; SI: v_cmp_ne_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, vcc
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI-NEXT: s_endpgm
+define void @zext_bool_icmp_ne_0(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp ne i32 %a, %b
+  %ext = zext i1 %icmp0 to i32
   %icmp1 = icmp ne i32 %ext, 0
   store i1 %icmp1, i1 addrspace(1)* %out
   ret void
 }
+
+; FUNC-LABEL: {{^}}zext_bool_icmp_eq_1:
+; SI-NOT: v_cmp
+; SI: v_cmp_eq_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, vcc
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI-NEXT: s_endpgm
+define void @zext_bool_icmp_eq_1(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp eq i32 %a, %b
+  %ext = zext i1 %icmp0 to i32
+  %icmp1 = icmp eq i32 %ext, 1
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zext_bool_icmp_ne_1:
+; SI-NOT: v_cmp
+; SI: v_cmp_eq_i32_e32 vcc,
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, vcc
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @zext_bool_icmp_ne_1(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp ne i32 %a, %b
+  %ext = zext i1 %icmp0 to i32
+  %icmp1 = icmp ne i32 %ext, 1
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}sext_bool_icmp_ne_k:
+; SI-DAG: s_load_dword [[A:s[0-9]+]], s{{\[[0-9]+:[0-9]+\]}}, 0xb
+; SI-DAG: s_load_dword [[B:s[0-9]+]], s{{\[[0-9]+:[0-9]+\]}}, 0xc
+; SI: v_mov_b32_e32 [[VB:v[0-9]+]], [[B]]
+; SI: v_cmp_ne_i32_e64 [[CMP:s\[[0-9]+:[0-9]+\]]], [[VB]], 2{{$}}
+; SI: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, [[CMP]]
+; SI: buffer_store_byte
+; SI: s_endpgm
+define void @sext_bool_icmp_ne_k(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp ne i32 %a, %b
+  %ext = sext i1 %icmp0 to i32
+  %icmp1 = icmp ne i32 %ext, 2
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}cmp_zext_k_i8max:
+; SI: buffer_load_ubyte [[B:v[0-9]+]], s{{\[[0-9]+:[0-9]+\]}}, 0 offset:0x2c
+; SI: v_mov_b32_e32 [[K255:v[0-9]+]], 0xff{{$}}
+; SI: v_cmp_ne_i32_e32 vcc, [[B]], [[K255]]
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, vcc
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI: s_endpgm
+define void @cmp_zext_k_i8max(i1 addrspace(1)* %out, i8 %b) nounwind {
+  %b.ext = zext i8 %b to i32
+  %icmp0 = icmp ne i32 %b.ext, 255
+  store i1 %icmp0, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}cmp_sext_k_neg1:
+; SI: buffer_load_sbyte [[B:v[0-9]+]]
+; SI: v_cmp_ne_i32_e64 [[CMP:s\[[0-9]+:[0-9]+\]]], [[B]], -1{{$}}
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, [[CMP]]
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI: s_endpgm
+define void @cmp_sext_k_neg1(i1 addrspace(1)* %out, i8 %b) nounwind {
+  %b.ext = sext i8 %b to i32
+  %icmp0 = icmp ne i32 %b.ext, -1
+  store i1 %icmp0, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}cmp_zext_k_neg1:
+; SI: v_mov_b32_e32 [[RESULT:v[0-9]+]], 1{{$}}
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI: s_endpgm
+define void @cmp_zext_k_neg1(i1 addrspace(1)* %out, i8 %b) nounwind {
+  %b.ext = zext i8 %b to i32
+  %icmp0 = icmp ne i32 %b.ext, -1
+  store i1 %icmp0, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zext_bool_icmp_ne_k:
+; SI: v_mov_b32_e32 [[RESULT:v[0-9]+]], 1{{$}}
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI-NEXT: s_endpgm
+define void @zext_bool_icmp_ne_k(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp ne i32 %a, %b
+  %ext = zext i1 %icmp0 to i32
+  %icmp1 = icmp ne i32 %ext, 2
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zext_bool_icmp_eq_k:
+; SI: v_mov_b32_e32 [[RESULT:v[0-9]+]], 0{{$}}
+; SI-NEXT: buffer_store_byte [[RESULT]]
+; SI-NEXT: s_endpgm
+define void @zext_bool_icmp_eq_k(i1 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %icmp0 = icmp ne i32 %a, %b
+  %ext = zext i1 %icmp0 to i32
+  %icmp1 = icmp eq i32 %ext, 2
+  store i1 %icmp1, i1 addrspace(1)* %out
+  ret void
+}

test/CodeGen/R600/trunc-cmp-constant.ll

+; RUN: llc -march=r600 -mcpu=SI -verify-machineinstrs < %s | FileCheck -check-prefix=SI -check-prefix=FUNC %s
+
+; FUNC-LABEL {{^}}sextload_i1_to_i32_trunc_cmp_eq_0:
+; SI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; SI: v_and_b32_e32 [[TMP:v[0-9]+]], 1, [[LOAD]]
+; SI: v_cmp_eq_i32_e64 [[CMP:s\[[0-9]+:[0-9]+\]]], [[TMP]], 1{{$}}
+; SI: v_cndmask_b32_e64
+; SI: v_cndmask_b32_e64
+; SI: buffer_store_byte
+define void @sextload_i1_to_i32_trunc_cmp_eq_0(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = sext i1 %load to i32
+  %cmp = icmp eq i32 %ext, 0
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FIXME: This should be one compare
+; FUNC-LABEL: {{^}}zextload_i1_to_i32_trunc_cmp_eq_0:
+; SI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; SI: v_and_b32_e32 [[TMP:v[0-9]+]], 1, [[LOAD]]
+; SI: v_cmp_eq_i32_e64 [[CMP0:s\[[0-9]+:[0-9]+\]]], [[TMP]], 1{{$}}
+; SI-NEXT: v_cndmask_b32_e64 [[TOI32:v[0-9]+]], 0, -1, [[CMP0]]
+; SI-NEXT: v_xor_b32_e32 [[NEG:v[0-9]+]], -1, [[TOI32]]
+; SI-NEXT: v_cmp_ne_i32_e64 [[CMP1:s\[[0-9]+:[0-9]+\]]], [[NEG]], 0
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, [[CMP1]]
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @zextload_i1_to_i32_trunc_cmp_eq_0(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = zext i1 %load to i32
+  %cmp = icmp eq i32 %ext, 0
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}sextload_i1_to_i32_trunc_cmp_eq_1:
+; SI: v_mov_b32_e32 [[RESULT:v[0-9]+]], 0{{$}}
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @sextload_i1_to_i32_trunc_cmp_eq_1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = sext i1 %load to i32
+  %cmp = icmp eq i32 %ext, 1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zextload_i1_to_i32_trunc_cmp_eq_1:
+; SI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; SI: v_and_b32_e32 [[RESULT:v[0-9]+]], 1, [[LOAD]]
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @zextload_i1_to_i32_trunc_cmp_eq_1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = zext i1 %load to i32
+  %cmp = icmp eq i32 %ext, 1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}sextload_i1_to_i32_trunc_cmp_eq_neg1:
+; SI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; SI: v_and_b32_e32 [[RESULT:v[0-9]+]], 1, [[LOAD]]
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @sextload_i1_to_i32_trunc_cmp_eq_neg1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = sext i1 %load to i32
+  %cmp = icmp eq i32 %ext, -1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zextload_i1_to_i32_trunc_cmp_eq_neg1:
+; SI: v_mov_b32_e32 [[RESULT:v[0-9]+]], 0{{$}}
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @zextload_i1_to_i32_trunc_cmp_eq_neg1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = zext i1 %load to i32
+  %cmp = icmp eq i32 %ext, -1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+
+; FUNC-LABEL {{^}}sextload_i1_to_i32_trunc_cmp_ne_0:
+; SI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; SI: v_and_b32_e32 [[TMP:v[0-9]+]], 1, [[LOAD]]
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @sextload_i1_to_i32_trunc_cmp_ne_0(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = sext i1 %load to i32
+  %cmp = icmp ne i32 %ext, 0
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zextload_i1_to_i32_trunc_cmp_ne_0:
+; SI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; SI: v_and_b32_e32 [[TMP:v[0-9]+]], 1, [[LOAD]]
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @zextload_i1_to_i32_trunc_cmp_ne_0(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = zext i1 %load to i32
+  %cmp = icmp ne i32 %ext, 0
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}sextload_i1_to_i32_trunc_cmp_ne_1:
+; SI: v_mov_b32_e32 [[RESULT:v[0-9]+]], 1{{$}}
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @sextload_i1_to_i32_trunc_cmp_ne_1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = sext i1 %load to i32
+  %cmp = icmp ne i32 %ext, 1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zextload_i1_to_i32_trunc_cmp_ne_1:
+; SI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; SI: v_and_b32_e32 [[TMP:v[0-9]+]], 1, [[LOAD]]
+; SI: v_cmp_eq_i32_e64 [[CMP0:s\[[0-9]+:[0-9]+\]]], [[TMP]], 1{{$}}
+; SI-NEXT: v_cndmask_b32_e64 [[TOI32:v[0-9]+]], 0, -1, [[CMP0]]
+; SI-NEXT: v_xor_b32_e32 [[NEG:v[0-9]+]], -1, [[TOI32]]
+; SI-NEXT: v_cmp_ne_i32_e64 [[CMP1:s\[[0-9]+:[0-9]+\]]], [[NEG]], 0
+; SI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, [[CMP1]]
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @zextload_i1_to_i32_trunc_cmp_ne_1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = zext i1 %load to i32
+  %cmp = icmp ne i32 %ext, 1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FIXME: This should be one compare.
+; FUNC-LABEL: {{^}}sextload_i1_to_i32_trunc_cmp_ne_neg1:
+; XSI: buffer_load_ubyte [[LOAD:v[0-9]+]]
+; XSI: v_and_b32_e32 [[TMP:v[0-9]+]], 1, [[LOAD]]
+; XSI: v_cmp_eq_i32_e64 [[CMP0:s\[[0-9]+:[0-9]+\]]], [[TMP]], 0{{$}}
+; XSI-NEXT: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, 1, [[CMP0]]
+; XSI-NEXT: buffer_store_byte [[RESULT]]
+define void @sextload_i1_to_i32_trunc_cmp_ne_neg1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = sext i1 %load to i32
+  %cmp = icmp ne i32 %ext, -1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}zextload_i1_to_i32_trunc_cmp_ne_neg1:
+; SI: v_mov_b32_e32 [[RESULT:v[0-9]+]], 1{{$}}
+; SI-NEXT: buffer_store_byte [[RESULT]]
+define void @zextload_i1_to_i32_trunc_cmp_ne_neg1(i1 addrspace(1)* %out, i1 addrspace(1)* %in) nounwind {
+  %load = load i1 addrspace(1)* %in
+  %ext = zext i1 %load to i32
+  %cmp = icmp ne i32 %ext, -1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: {{^}}masked_load_i1_to_i32_trunc_cmp_ne_neg1:
+; SI: buffer_load_sbyte [[LOAD:v[0-9]+]]
+; SI: v_cmp_ne_i32_e64 {{s\[[0-9]+:[0-9]+\]}}, [[LOAD]], -1{{$}}
+; SI-NEXT: v_cndmask_b32_e64
+; SI-NEXT: buffer_store_byte
+define void @masked_load_i1_to_i32_trunc_cmp_ne_neg1(i1 addrspace(1)* %out, i8 addrspace(1)* %in) nounwind {
+  %load = load i8 addrspace(1)* %in
+  %masked = and i8 %load, 255
+  %ext = sext i8 %masked to i32
+  %cmp = icmp ne i32 %ext, -1
+  store i1 %cmp, i1 addrspace(1)* %out
+  ret void
+}

test/CodeGen/X86/shrink-compare.ll

 ; CHECK-NOT: cmpl $1,{{.*}}x+4
 ; CHECK: ret
 }
+
+; CHECK-LABEL: test2_1:
+; CHECK: movzbl
+; CHECK: cmpl $256
+; CHECK: jne
+define void @test2_1(i32 %X) nounwind minsize {
+entry:
+  %and = and i32 %X, 255
+  %cmp = icmp eq i32 %and, 256
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_1:
+; CHECK: cmpb $1, %{{dil|cl}}
+define void @test_sext_i8_icmp_1(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, 1
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_47:
+; CHECK: cmpb $47, %{{dil|cl}}
+define void @test_sext_i8_icmp_47(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, 47
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_127:
+; CHECK: cmpb $127, %{{dil|cl}}
+define void @test_sext_i8_icmp_127(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, 127
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_neg1:
+; CHECK: cmpb $-1, %{{dil|cl}}
+define void @test_sext_i8_icmp_neg1(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, -1
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_neg2:
+; CHECK: cmpb $-2, %{{dil|cl}}
+define void @test_sext_i8_icmp_neg2(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, -2
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_neg127:
+; CHECK: cmpb $-127, %{{dil|cl}}
+define void @test_sext_i8_icmp_neg127(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, -127
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_neg128:
+; CHECK: cmpb $-128, %{{dil|cl}}
+define void @test_sext_i8_icmp_neg128(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, -128
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+; CHECK-LABEL: test_sext_i8_icmp_255:
+; CHECK: movb $1,
+; CHECK: testb
+; CHECK: jne
+define void @test_sext_i8_icmp_255(i8 %x) nounwind minsize {
+entry:
+  %sext = sext i8 %x to i32
+  %cmp = icmp eq i32 %sext, 255
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  tail call void @bar() nounwind
+  br label %if.end
+
+if.end:
+  ret void
+}