[llvm] 29ae448 - [PowerPC] Handle STRICT_FSETCC(S) in more cases

Qiu Chaofan via llvm-commits llvm-commits at lists.llvm.org
Tue Sep 1 09:33:35 PDT 2020


Author: Qiu Chaofan
Date: 2020-09-02T00:33:21+08:00
New Revision: 29ae4485950ed76faa94dabbd13bbe91d2b5c750

URL: https://github.com/llvm/llvm-project/commit/29ae4485950ed76faa94dabbd13bbe91d2b5c750
DIFF: https://github.com/llvm/llvm-project/commit/29ae4485950ed76faa94dabbd13bbe91d2b5c750.diff

LOG: [PowerPC] Handle STRICT_FSETCC(S) in more cases

On -O0, i1 strict_fsetcc will be promoted to i32. We don't handle that
in TD patterns. This patch fills logic in PPCISelDAGToDAG to handle more
cases.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D86595

Added: 
    llvm/test/CodeGen/PowerPC/fp-strict-fcmp-noopt.ll

Modified: 
    llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 51ff0da6c091..62bb5cc1e806 100644
--- a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -218,7 +218,7 @@ namespace {
     /// SelectCC - Select a comparison of the specified values with the
     /// specified condition code, returning the CR# of the expression.
     SDValue SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
-                     const SDLoc &dl);
+                     const SDLoc &dl, SDValue Chain = SDValue());
 
     /// SelectAddrImmOffs - Return true if the operand is valid for a preinc
     /// immediate field.  Note that the operand at this point is already the
@@ -3710,7 +3710,7 @@ bool PPCDAGToDAGISel::tryBitPermutation(SDNode *N) {
 /// SelectCC - Select a comparison of the specified values with the specified
 /// condition code, returning the CR# of the expression.
 SDValue PPCDAGToDAGISel::SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
-                                  const SDLoc &dl) {
+                                  const SDLoc &dl, SDValue Chain) {
   // Always select the LHS.
   unsigned Opc;
 
@@ -3863,7 +3863,12 @@ SDValue PPCDAGToDAGISel::SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
     assert(Subtarget->hasVSX() && "__float128 requires VSX");
     Opc = PPC::XSCMPUQP;
   }
-  return SDValue(CurDAG->getMachineNode(Opc, dl, MVT::i32, LHS, RHS), 0);
+  if (Chain)
+    return SDValue(
+        CurDAG->getMachineNode(Opc, dl, MVT::i32, MVT::Other, LHS, RHS, Chain),
+        0);
+  else
+    return SDValue(CurDAG->getMachineNode(Opc, dl, MVT::i32, LHS, RHS), 0);
 }
 
 static PPC::Predicate getPredicateForSetCC(ISD::CondCode CC, const EVT &VT,
@@ -4050,17 +4055,23 @@ static unsigned int getVCmpInst(MVT VecVT, ISD::CondCode CC,
 bool PPCDAGToDAGISel::trySETCC(SDNode *N) {
   SDLoc dl(N);
   unsigned Imm;
-  ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
+  bool IsStrict = N->isStrictFPOpcode();
+  ISD::CondCode CC =
+      cast<CondCodeSDNode>(N->getOperand(IsStrict ? 3 : 2))->get();
   EVT PtrVT =
       CurDAG->getTargetLoweringInfo().getPointerTy(CurDAG->getDataLayout());
   bool isPPC64 = (PtrVT == MVT::i64);
+  SDValue Chain = IsStrict ? N->getOperand(0) : SDValue();
+
+  SDValue LHS = N->getOperand(IsStrict ? 1 : 0);
+  SDValue RHS = N->getOperand(IsStrict ? 2 : 1);
 
-  if (!Subtarget->useCRBits() && isInt32Immediate(N->getOperand(1), Imm)) {
+  if (!IsStrict && !Subtarget->useCRBits() && isInt32Immediate(RHS, Imm)) {
     // We can codegen setcc op, imm very efficiently compared to a brcond.
     // Check for those cases here.
     // setcc op, 0
     if (Imm == 0) {
-      SDValue Op = N->getOperand(0);
+      SDValue Op = LHS;
       switch (CC) {
       default: break;
       case ISD::SETEQ: {
@@ -4095,7 +4106,7 @@ bool PPCDAGToDAGISel::trySETCC(SDNode *N) {
       }
       }
     } else if (Imm == ~0U) {        // setcc op, -1
-      SDValue Op = N->getOperand(0);
+      SDValue Op = LHS;
       switch (CC) {
       default: break;
       case ISD::SETEQ:
@@ -4138,12 +4149,9 @@ bool PPCDAGToDAGISel::trySETCC(SDNode *N) {
     }
   }
 
-  SDValue LHS = N->getOperand(0);
-  SDValue RHS = N->getOperand(1);
-
   // Altivec Vector compare instructions do not set any CR register by default and
   // vector compare operations return the same type as the operands.
-  if (LHS.getValueType().isVector()) {
+  if (!IsStrict && LHS.getValueType().isVector()) {
     if (Subtarget->hasSPE())
       return false;
 
@@ -4171,7 +4179,9 @@ bool PPCDAGToDAGISel::trySETCC(SDNode *N) {
 
   bool Inv;
   unsigned Idx = getCRIdxForSetCC(CC, Inv);
-  SDValue CCReg = SelectCC(LHS, RHS, CC, dl);
+  SDValue CCReg = SelectCC(LHS, RHS, CC, dl, Chain);
+  if (IsStrict)
+    CurDAG->ReplaceAllUsesOfValueWith(SDValue(N, 1), CCReg.getValue(1));
   SDValue IntCR;
 
   // SPE e*cmp* instructions only set the 'gt' bit, so hard-code that
@@ -4664,6 +4674,8 @@ void PPCDAGToDAGISel::Select(SDNode *N) {
     break;
 
   case ISD::SETCC:
+  case ISD::STRICT_FSETCC:
+  case ISD::STRICT_FSETCCS:
     if (trySETCC(N))
       return;
     break;

diff  --git a/llvm/test/CodeGen/PowerPC/fp-strict-fcmp-noopt.ll b/llvm/test/CodeGen/PowerPC/fp-strict-fcmp-noopt.ll
new file mode 100644
index 000000000000..e6bc0f4bd769
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/fp-strict-fcmp-noopt.ll
@@ -0,0 +1,140 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs -ppc-asm-full-reg-names -ppc-vsr-nums-as-vr \
+; RUN:   < %s -mtriple=powerpc64-unknown-linux -mcpu=pwr9 -O0 | FileCheck %s
+
+define i32 @une_ppcf128(ppc_fp128 %a, ppc_fp128 %b) #0 {
+; CHECK-LABEL: une_ppcf128:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    xscmpudp cr7, f1, f3
+; CHECK-NEXT:    mfocrf r3, 1
+; CHECK-NEXT:    rlwinm r3, r3, 31, 31, 31
+; CHECK-NEXT:    xscmpudp cr7, f2, f4
+; CHECK-NEXT:    mfocrf r4, 1
+; CHECK-NEXT:    rlwinm r4, r4, 31, 31, 31
+; CHECK-NEXT:    xori r4, r4, 1
+; CHECK-NEXT:    and r3, r3, r4
+; CHECK-NEXT:    xscmpudp cr7, f1, f3
+; CHECK-NEXT:    mfocrf r4, 1
+; CHECK-NEXT:    rlwinm r4, r4, 31, 31, 31
+; CHECK-NEXT:    xori r4, r4, 1
+; CHECK-NEXT:    xscmpudp cr7, f1, f3
+; CHECK-NEXT:    mfocrf r5, 1
+; CHECK-NEXT:    rlwinm r5, r5, 31, 31, 31
+; CHECK-NEXT:    xori r5, r5, 1
+; CHECK-NEXT:    and r4, r4, r5
+; CHECK-NEXT:    or r3, r4, r3
+; CHECK-NEXT:    # kill: def $r4 killed $r3
+; CHECK-NEXT:    clrldi r3, r3, 32
+; CHECK-NEXT:    blr
+entry:
+  %0 = call i1 @llvm.experimental.constrained.fcmp.ppcf128(ppc_fp128 %a, ppc_fp128 %b, metadata !"une", metadata !"fpexcept.strict") #0
+  %1 = zext i1 %0 to i32
+  ret i32 %1
+}
+
+; This is a 
diff erent branch from une
+define i32 @ogt_ppcf128(ppc_fp128 %a, ppc_fp128 %b) #0 {
+; CHECK-LABEL: ogt_ppcf128:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    xscmpudp cr7, f1, f3
+; CHECK-NEXT:    mfocrf r3, 1
+; CHECK-NEXT:    rlwinm r3, r3, 31, 31, 31
+; CHECK-NEXT:    xscmpudp cr7, f2, f4
+; CHECK-NEXT:    mfocrf r4, 1
+; CHECK-NEXT:    rlwinm r4, r4, 30, 31, 31
+; CHECK-NEXT:    and r3, r3, r4
+; CHECK-NEXT:    xscmpudp cr7, f1, f3
+; CHECK-NEXT:    xscmpudp cr0, f1, f3
+; CHECK-NEXT:    mfocrf r4, 1
+; CHECK-NEXT:    rotlwi r4, r4, 28
+; CHECK-NEXT:    stw r4, -4(r1)
+; CHECK-NEXT:    mcrf cr7, cr0
+; CHECK-NEXT:    mfocrf r4, 1
+; CHECK-NEXT:    rlwinm r4, r4, 30, 31, 31
+; CHECK-NEXT:    lwz r5, -4(r1)
+; CHECK-NEXT:    rotlwi r5, r5, 4
+; CHECK-NEXT:    mtocrf 1, r5
+; CHECK-NEXT:    mfocrf r5, 1
+; CHECK-NEXT:    rlwinm r5, r5, 31, 31, 31
+; CHECK-NEXT:    xori r5, r5, 1
+; CHECK-NEXT:    and r4, r5, r4
+; CHECK-NEXT:    or r3, r4, r3
+; CHECK-NEXT:    # kill: def $r4 killed $r3
+; CHECK-NEXT:    clrldi r3, r3, 32
+; CHECK-NEXT:    blr
+entry:
+  %0 = call i1 @llvm.experimental.constrained.fcmp.ppcf128(ppc_fp128 %a, ppc_fp128 %b, metadata !"ogt", metadata !"fpexcept.strict") #0
+  %1 = zext i1 %0 to i32
+  ret i32 %1
+}
+
+define i1 @test_f128(fp128 %a, fp128 %b) #0 {
+; CHECK-LABEL: test_f128:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    xscmpuqp cr7, v2, v3
+; CHECK-NEXT:    mfocrf r3, 1
+; CHECK-NEXT:    rlwinm r3, r3, 31, 31, 31
+; CHECK-NEXT:    xori r3, r3, 1
+; CHECK-NEXT:    # implicit-def: $x4
+; CHECK-NEXT:    mr r4, r3
+; CHECK-NEXT:    mr r3, r4
+; CHECK-NEXT:    blr
+entry:
+  %0 = call i1 @llvm.experimental.constrained.fcmp.f128(fp128 %a, fp128 %b, metadata !"une", metadata !"fpexcept.strict") #0
+  ret i1 %0
+}
+
+define i1 @testbr_f64(double %a, double %b) #0 {
+; CHECK-LABEL: testbr_f64:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    xscmpudp cr7, f1, f2
+; CHECK-NEXT:    mfocrf r3, 1
+; CHECK-NEXT:    rlwinm r3, r3, 31, 31, 31
+; CHECK-NEXT:    cmplwi r3, 0
+; CHECK-NEXT:    bne cr0, .LBB3_2
+; CHECK-NEXT:    b .LBB3_1
+; CHECK-NEXT:  .LBB3_1: # %tr
+; CHECK-NEXT:    li r3, -1
+; CHECK-NEXT:    blr
+; CHECK-NEXT:  .LBB3_2: # %fl
+; CHECK-NEXT:    li r3, 0
+; CHECK-NEXT:    blr
+entry:
+  %0 = call i1 @llvm.experimental.constrained.fcmp.f64(double %a, double %b, metadata !"une", metadata !"fpexcept.strict") #0
+  br i1 %0, label %tr, label %fl
+tr:
+  ret i1 true
+fl:
+  ret i1 false
+}
+
+define i1 @testbr_f32(float %a, float %b) #0 {
+; CHECK-LABEL: testbr_f32:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    fcmpu cr7, f1, f2
+; CHECK-NEXT:    mfocrf r3, 1
+; CHECK-NEXT:    rlwinm r3, r3, 31, 31, 31
+; CHECK-NEXT:    cmplwi r3, 0
+; CHECK-NEXT:    bne cr0, .LBB4_2
+; CHECK-NEXT:    b .LBB4_1
+; CHECK-NEXT:  .LBB4_1: # %tr
+; CHECK-NEXT:    li r3, -1
+; CHECK-NEXT:    blr
+; CHECK-NEXT:  .LBB4_2: # %fl
+; CHECK-NEXT:    li r3, 0
+; CHECK-NEXT:    blr
+entry:
+  %0 = call i1 @llvm.experimental.constrained.fcmp.f32(float %a, float %b, metadata !"une", metadata !"fpexcept.strict") #0
+  br i1 %0, label %tr, label %fl
+tr:
+  ret i1 true
+fl:
+  ret i1 false
+}
+
+declare i1 @llvm.experimental.constrained.fcmp.ppcf128(ppc_fp128, ppc_fp128, metadata, metadata)
+declare i1 @llvm.experimental.constrained.fcmp.f128(fp128, fp128, metadata, metadata)
+declare i1 @llvm.experimental.constrained.fcmp.f64(double, double, metadata, metadata)
+declare i1 @llvm.experimental.constrained.fcmp.f32(float, float, metadata, metadata)
+
+attributes #0 = { strictfp }


        


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