[llvm] r189653 - Teach X86 backend to create BMI2 BZHI instructions from (and X, (add (shl 1, Y), -1)). Fixes PR17038.
Craig Topper
craig.topper at gmail.com
Thu Aug 29 23:52:22 PDT 2013
Author: ctopper
Date: Fri Aug 30 01:52:21 2013
New Revision: 189653
URL: http://llvm.org/viewvc/llvm-project?rev=189653&view=rev
Log:
Teach X86 backend to create BMI2 BZHI instructions from (and X, (add (shl 1, Y), -1)). Fixes PR17038.
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/lib/Target/X86/X86ISelLowering.h
llvm/trunk/lib/Target/X86/X86InstrInfo.td
llvm/trunk/test/CodeGen/X86/bmi.ll
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=189653&r1=189652&r2=189653&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Fri Aug 30 01:52:21 2013
@@ -13473,6 +13473,7 @@ const char *X86TargetLowering::getTarget
case X86ISD::BLSI: return "X86ISD::BLSI";
case X86ISD::BLSMSK: return "X86ISD::BLSMSK";
case X86ISD::BLSR: return "X86ISD::BLSR";
+ case X86ISD::BZHI: return "X86ISD::BZHI";
case X86ISD::MUL_IMM: return "X86ISD::MUL_IMM";
case X86ISD::PTEST: return "X86ISD::PTEST";
case X86ISD::TESTP: return "X86ISD::TESTP";
@@ -17279,33 +17280,64 @@ static SDValue PerformAndCombine(SDNode
if (R.getNode())
return R;
- // Create BLSI, and BLSR instructions
+ // Create BLSI, BLSR, and BZHI instructions
// BLSI is X & (-X)
// BLSR is X & (X-1)
- if (Subtarget->hasBMI() && (VT == MVT::i32 || VT == MVT::i64)) {
+ // BZHI is X & ((1 << Y) - 1)
+ if (VT == MVT::i32 || VT == MVT::i64) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDLoc DL(N);
- // Check LHS for neg
- if (N0.getOpcode() == ISD::SUB && N0.getOperand(1) == N1 &&
- isZero(N0.getOperand(0)))
- return DAG.getNode(X86ISD::BLSI, DL, VT, N1);
-
- // Check RHS for neg
- if (N1.getOpcode() == ISD::SUB && N1.getOperand(1) == N0 &&
- isZero(N1.getOperand(0)))
- return DAG.getNode(X86ISD::BLSI, DL, VT, N0);
-
- // Check LHS for X-1
- if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1 &&
- isAllOnes(N0.getOperand(1)))
- return DAG.getNode(X86ISD::BLSR, DL, VT, N1);
-
- // Check RHS for X-1
- if (N1.getOpcode() == ISD::ADD && N1.getOperand(0) == N0 &&
- isAllOnes(N1.getOperand(1)))
- return DAG.getNode(X86ISD::BLSR, DL, VT, N0);
+ if (Subtarget->hasBMI()) {
+ // Check LHS for neg
+ if (N0.getOpcode() == ISD::SUB && N0.getOperand(1) == N1 &&
+ isZero(N0.getOperand(0)))
+ return DAG.getNode(X86ISD::BLSI, DL, VT, N1);
+
+ // Check RHS for neg
+ if (N1.getOpcode() == ISD::SUB && N1.getOperand(1) == N0 &&
+ isZero(N1.getOperand(0)))
+ return DAG.getNode(X86ISD::BLSI, DL, VT, N0);
+
+ // Check LHS for X-1
+ if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1 &&
+ isAllOnes(N0.getOperand(1)))
+ return DAG.getNode(X86ISD::BLSR, DL, VT, N1);
+
+ // Check RHS for X-1
+ if (N1.getOpcode() == ISD::ADD && N1.getOperand(0) == N0 &&
+ isAllOnes(N1.getOperand(1)))
+ return DAG.getNode(X86ISD::BLSR, DL, VT, N0);
+ }
+
+ if (Subtarget->hasBMI2()) {
+ // Check for (and (add (shl 1, Y), -1), X)
+ if (N0.getOpcode() == ISD::ADD && isAllOnes(N0.getOperand(1))) {
+ SDValue N00 = N0.getOperand(0);
+ if (N00.getOpcode() == ISD::SHL) {
+ SDValue N001 = N00.getOperand(1);
+ assert(N001.getValueType() == MVT::i8 && "unexpected type");
+ ConstantSDNode *C = dyn_cast<ConstantSDNode>(N00.getOperand(0));
+ if (C && C->getZExtValue() == 1)
+ return DAG.getNode(X86ISD::BZHI, DL, VT, N1,
+ DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N001));
+ }
+ }
+
+ // Check for (and X, (add (shl 1, Y), -1))
+ if (N1.getOpcode() == ISD::ADD && isAllOnes(N1.getOperand(1))) {
+ SDValue N10 = N1.getOperand(0);
+ if (N10.getOpcode() == ISD::SHL) {
+ SDValue N101 = N10.getOperand(1);
+ assert(N101.getValueType() == MVT::i8 && "unexpected type");
+ ConstantSDNode *C = dyn_cast<ConstantSDNode>(N10.getOperand(0));
+ if (C && C->getZExtValue() == 1)
+ return DAG.getNode(X86ISD::BZHI, DL, VT, N0,
+ DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N101));
+ }
+ }
+ }
return SDValue();
}
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.h?rev=189653&r1=189652&r2=189653&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.h (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.h Fri Aug 30 01:52:21 2013
@@ -295,6 +295,7 @@ namespace llvm {
BLSI, // BLSI - Extract lowest set isolated bit
BLSMSK, // BLSMSK - Get mask up to lowest set bit
BLSR, // BLSR - Reset lowest set bit
+ BZHI, // BZHI - Zero high bits
UMUL, // LOW, HI, FLAGS = umul LHS, RHS
Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.td?rev=189653&r1=189652&r2=189653&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.td Fri Aug 30 01:52:21 2013
@@ -253,6 +253,7 @@ def X86andn_flag : SDNode<"X86ISD::ANDN"
def X86blsi : SDNode<"X86ISD::BLSI", SDTIntUnaryOp>;
def X86blsmsk : SDNode<"X86ISD::BLSMSK", SDTIntUnaryOp>;
def X86blsr : SDNode<"X86ISD::BLSR", SDTIntUnaryOp>;
+def X86bzhi : SDNode<"X86ISD::BZHI", SDTIntBinOp>;
def X86mul_imm : SDNode<"X86ISD::MUL_IMM", SDTIntBinOp>;
@@ -1856,6 +1857,15 @@ let Predicates = [HasBMI2], Defs = [EFLA
int_x86_bmi_bzhi_64, loadi64>, VEX_W;
}
+def : Pat<(X86bzhi GR32:$src1, GR32:$src2),
+ (BZHI32rr GR32:$src1, GR32:$src2)>;
+def : Pat<(X86bzhi (loadi32 addr:$src1), GR32:$src2),
+ (BZHI32rm addr:$src1, GR32:$src2)>;
+def : Pat<(X86bzhi GR64:$src1, GR64:$src2),
+ (BZHI64rr GR64:$src1, GR64:$src2)>;
+def : Pat<(X86bzhi (loadi64 addr:$src1), GR64:$src2),
+ (BZHI64rm addr:$src1, GR64:$src2)>;
+
multiclass bmi_pdep_pext<string mnemonic, RegisterClass RC,
X86MemOperand x86memop, Intrinsic Int,
PatFrag ld_frag> {
Modified: llvm/trunk/test/CodeGen/X86/bmi.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/bmi.ll?rev=189653&r1=189652&r2=189653&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/bmi.ll (original)
+++ llvm/trunk/test/CodeGen/X86/bmi.ll Fri Aug 30 01:52:21 2013
@@ -146,6 +146,51 @@ define i64 @bzhi64(i64 %x, i64 %y) nounw
declare i64 @llvm.x86.bmi.bzhi.64(i64, i64) nounwind readnone
+define i32 @bzhi32b(i32 %x, i8 zeroext %index) #0 {
+entry:
+ %conv = zext i8 %index to i32
+ %shl = shl i32 1, %conv
+ %sub = add nsw i32 %shl, -1
+ %and = and i32 %sub, %x
+ ret i32 %and
+; CHECK-LABEL: bzhi32b:
+; CHECK: bzhil
+}
+
+define i32 @bzhi32b_load(i32* %w, i8 zeroext %index) #0 {
+entry:
+ %x = load i32* %w
+ %conv = zext i8 %index to i32
+ %shl = shl i32 1, %conv
+ %sub = add nsw i32 %shl, -1
+ %and = and i32 %sub, %x
+ ret i32 %and
+; CHECK-LABEL: bzhi32b_load:
+; CHECK: bzhil {{.*}}, ({{.*}}), {{.*}}
+}
+
+define i32 @bzhi32c(i32 %x, i8 zeroext %index) #0 {
+entry:
+ %conv = zext i8 %index to i32
+ %shl = shl i32 1, %conv
+ %sub = add nsw i32 %shl, -1
+ %and = and i32 %x, %sub
+ ret i32 %and
+; CHECK-LABEL: bzhi32c:
+; CHECK: bzhil
+}
+
+define i64 @bzhi64b(i64 %x, i8 zeroext %index) #0 {
+entry:
+ %conv = zext i8 %index to i64
+ %shl = shl i64 1, %conv
+ %sub = add nsw i64 %shl, -1
+ %and = and i64 %x, %sub
+ ret i64 %and
+; CHECK-LABEL: bzhi64b:
+; CHECK: bzhiq
+}
+
define i32 @blsi32(i32 %x) nounwind readnone {
%tmp = sub i32 0, %x
%tmp2 = and i32 %x, %tmp
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