[llvm] r214470 - [FastISel][AArch64] Fix the immediate versions of the {s|u}{add|sub}.with.overflow intrinsics.
Juergen Ributzka
juergen at apple.com
Thu Jul 31 18:25:56 PDT 2014
Author: ributzka
Date: Thu Jul 31 20:25:55 2014
New Revision: 214470
URL: http://llvm.org/viewvc/llvm-project?rev=214470&view=rev
Log:
[FastISel][AArch64] Fix the immediate versions of the {s|u}{add|sub}.with.overflow intrinsics.
ADDS and SUBS cannot encode negative immediates or immediates larger than 12bit.
This fix checks if the immediate version can be used under this constraints and
if we can convert ADDS to SUBS or vice versa to support negative immediates.
Also update the test cases to test the immediate versions.
Modified:
llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp
llvm/trunk/test/CodeGen/AArch64/arm64-xaluo.ll
Modified: llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp?rev=214470&r1=214469&r2=214470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp Thu Jul 31 20:25:55 2014
@@ -1759,59 +1759,53 @@ bool AArch64FastISel::FastLowerIntrinsic
return false;
bool LHSIsKill = hasTrivialKill(LHS);
- unsigned RHSReg = 0;
- bool RHSIsKill = false;
- bool UseImm = true;
- if (!isa<ConstantInt>(RHS)) {
- RHSReg = getRegForValue(RHS);
- if (!RHSReg)
- return false;
- RHSIsKill = hasTrivialKill(RHS);
- UseImm = false;
+ // Check if the immediate can be encoded in the instruction and if we should
+ // invert the instruction (adds -> subs) to handle negative immediates.
+ bool UseImm = false;
+ bool UseInverse = false;
+ uint64_t Imm = 0;
+ if (const auto *C = dyn_cast<ConstantInt>(RHS)) {
+ if (C->isNegative()) {
+ UseInverse = true;
+ Imm = -(C->getSExtValue());
+ } else
+ Imm = C->getZExtValue();
+
+ if (isUInt<12>(Imm))
+ UseImm = true;
+
+ UseInverse = UseImm && UseInverse;
}
+ static const unsigned OpcTable[2][2][2] = {
+ { {AArch64::ADDSWrr, AArch64::ADDSXrr},
+ {AArch64::ADDSWri, AArch64::ADDSXri} },
+ { {AArch64::SUBSWrr, AArch64::SUBSXrr},
+ {AArch64::SUBSWri, AArch64::SUBSXri} }
+ };
unsigned Opc = 0;
unsigned MulReg = 0;
+ unsigned RHSReg = 0;
+ bool RHSIsKill = false;
AArch64CC::CondCode CC = AArch64CC::Invalid;
bool Is64Bit = VT == MVT::i64;
switch (II->getIntrinsicID()) {
default: llvm_unreachable("Unexpected intrinsic!");
case Intrinsic::sadd_with_overflow:
- if (UseImm)
- Opc = Is64Bit ? AArch64::ADDSXri : AArch64::ADDSWri;
- else
- Opc = Is64Bit ? AArch64::ADDSXrr : AArch64::ADDSWrr;
- CC = AArch64CC::VS;
- break;
+ Opc = OpcTable[UseInverse][UseImm][Is64Bit]; CC = AArch64CC::VS; break;
case Intrinsic::uadd_with_overflow:
- if (UseImm)
- Opc = Is64Bit ? AArch64::ADDSXri : AArch64::ADDSWri;
- else
- Opc = Is64Bit ? AArch64::ADDSXrr : AArch64::ADDSWrr;
- CC = AArch64CC::HS;
- break;
+ Opc = OpcTable[UseInverse][UseImm][Is64Bit]; CC = AArch64CC::HS; break;
case Intrinsic::ssub_with_overflow:
- if (UseImm)
- Opc = Is64Bit ? AArch64::SUBSXri : AArch64::SUBSWri;
- else
- Opc = Is64Bit ? AArch64::SUBSXrr : AArch64::SUBSWrr;
- CC = AArch64CC::VS;
- break;
+ Opc = OpcTable[!UseInverse][UseImm][Is64Bit]; CC = AArch64CC::VS; break;
case Intrinsic::usub_with_overflow:
- if (UseImm)
- Opc = Is64Bit ? AArch64::SUBSXri : AArch64::SUBSWri;
- else
- Opc = Is64Bit ? AArch64::SUBSXrr : AArch64::SUBSWrr;
- CC = AArch64CC::LO;
- break;
+ Opc = OpcTable[!UseInverse][UseImm][Is64Bit]; CC = AArch64CC::LO; break;
case Intrinsic::smul_with_overflow: {
CC = AArch64CC::NE;
- if (UseImm) {
- RHSReg = getRegForValue(RHS);
- if (!RHSReg)
- return false;
- RHSIsKill = hasTrivialKill(RHS);
- }
+ RHSReg = getRegForValue(RHS);
+ if (!RHSReg)
+ return false;
+ RHSIsKill = hasTrivialKill(RHS);
+
if (VT == MVT::i32) {
MulReg = Emit_SMULL_rr(MVT::i64, LHSReg, LHSIsKill, RHSReg, RHSIsKill);
unsigned ShiftReg = Emit_LSR_ri(MVT::i64, MulReg, false, 32);
@@ -1841,12 +1835,11 @@ bool AArch64FastISel::FastLowerIntrinsic
}
case Intrinsic::umul_with_overflow: {
CC = AArch64CC::NE;
- if (UseImm) {
- RHSReg = getRegForValue(RHS);
- if (!RHSReg)
- return false;
- RHSIsKill = hasTrivialKill(RHS);
- }
+ RHSReg = getRegForValue(RHS);
+ if (!RHSReg)
+ return false;
+ RHSIsKill = hasTrivialKill(RHS);
+
if (VT == MVT::i32) {
MulReg = Emit_UMULL_rr(MVT::i64, LHSReg, LHSIsKill, RHSReg, RHSIsKill);
unsigned CmpReg = createResultReg(TLI.getRegClassFor(MVT::i64));
@@ -1872,15 +1865,23 @@ bool AArch64FastISel::FastLowerIntrinsic
}
}
+ if (!UseImm) {
+ RHSReg = getRegForValue(RHS);
+ if (!RHSReg)
+ return false;
+ RHSIsKill = hasTrivialKill(RHS);
+ }
+
unsigned ResultReg = createResultReg(TLI.getRegClassFor(VT));
if (Opc) {
MachineInstrBuilder MIB;
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc),
ResultReg)
.addReg(LHSReg, getKillRegState(LHSIsKill));
- if (UseImm)
- MIB.addImm(cast<ConstantInt>(RHS)->getZExtValue());
- else
+ if (UseImm) {
+ MIB.addImm(Imm);
+ MIB.addImm(0);
+ } else
MIB.addReg(RHSReg, getKillRegState(RHSIsKill));
}
else
Modified: llvm/trunk/test/CodeGen/AArch64/arm64-xaluo.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/arm64-xaluo.ll?rev=214470&r1=214469&r2=214470&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/arm64-xaluo.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/arm64-xaluo.ll Thu Jul 31 20:25:55 2014
@@ -4,9 +4,9 @@
;
; Get the actual value of the overflow bit.
;
-define zeroext i1 @saddo.i32(i32 %v1, i32 %v2, i32* %res) {
+define zeroext i1 @saddo1.i32(i32 %v1, i32 %v2, i32* %res) {
entry:
-; CHECK-LABEL: saddo.i32
+; CHECK-LABEL: saddo1.i32
; CHECK: adds {{w[0-9]+}}, w0, w1
; CHECK-NEXT: cset {{w[0-9]+}}, vs
%t = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %v1, i32 %v2)
@@ -16,9 +16,48 @@ entry:
ret i1 %obit
}
-define zeroext i1 @saddo.i64(i64 %v1, i64 %v2, i64* %res) {
+; Test the immediate version.
+define zeroext i1 @saddo2.i32(i32 %v1, i32* %res) {
entry:
-; CHECK-LABEL: saddo.i64
+; CHECK-LABEL: saddo2.i32
+; CHECK: adds {{w[0-9]+}}, w0, #4
+; CHECK-NEXT: cset {{w[0-9]+}}, vs
+ %t = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %v1, i32 4)
+ %val = extractvalue {i32, i1} %t, 0
+ %obit = extractvalue {i32, i1} %t, 1
+ store i32 %val, i32* %res
+ ret i1 %obit
+}
+
+; Test negative immediates.
+define zeroext i1 @saddo3.i32(i32 %v1, i32* %res) {
+entry:
+; CHECK-LABEL: saddo3.i32
+; CHECK: subs {{w[0-9]+}}, w0, #4
+; CHECK-NEXT: cset {{w[0-9]+}}, vs
+ %t = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %v1, i32 -4)
+ %val = extractvalue {i32, i1} %t, 0
+ %obit = extractvalue {i32, i1} %t, 1
+ store i32 %val, i32* %res
+ ret i1 %obit
+}
+
+; Test immediates that are too large to be encoded.
+define zeroext i1 @saddo4.i32(i32 %v1, i32* %res) {
+entry:
+; CHECK-LABEL: saddo4.i32
+; CHECK: adds {{w[0-9]+}}, w0, {{w[0-9]+}}
+; CHECK-NEXT: cset {{w[0-9]+}}, vs
+ %t = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %v1, i32 16777215)
+ %val = extractvalue {i32, i1} %t, 0
+ %obit = extractvalue {i32, i1} %t, 1
+ store i32 %val, i32* %res
+ ret i1 %obit
+}
+
+define zeroext i1 @saddo1.i64(i64 %v1, i64 %v2, i64* %res) {
+entry:
+; CHECK-LABEL: saddo1.i64
; CHECK: adds {{x[0-9]+}}, x0, x1
; CHECK-NEXT: cset {{w[0-9]+}}, vs
%t = call {i64, i1} @llvm.sadd.with.overflow.i64(i64 %v1, i64 %v2)
@@ -28,6 +67,30 @@ entry:
ret i1 %obit
}
+define zeroext i1 @saddo2.i64(i64 %v1, i64* %res) {
+entry:
+; CHECK-LABEL: saddo2.i64
+; CHECK: adds {{x[0-9]+}}, x0, #4
+; CHECK-NEXT: cset {{w[0-9]+}}, vs
+ %t = call {i64, i1} @llvm.sadd.with.overflow.i64(i64 %v1, i64 4)
+ %val = extractvalue {i64, i1} %t, 0
+ %obit = extractvalue {i64, i1} %t, 1
+ store i64 %val, i64* %res
+ ret i1 %obit
+}
+
+define zeroext i1 @saddo3.i64(i64 %v1, i64* %res) {
+entry:
+; CHECK-LABEL: saddo3.i64
+; CHECK: subs {{x[0-9]+}}, x0, #4
+; CHECK-NEXT: cset {{w[0-9]+}}, vs
+ %t = call {i64, i1} @llvm.sadd.with.overflow.i64(i64 %v1, i64 -4)
+ %val = extractvalue {i64, i1} %t, 0
+ %obit = extractvalue {i64, i1} %t, 1
+ store i64 %val, i64* %res
+ ret i1 %obit
+}
+
define zeroext i1 @uaddo.i32(i32 %v1, i32 %v2, i32* %res) {
entry:
; CHECK-LABEL: uaddo.i32
@@ -52,15 +115,27 @@ entry:
ret i1 %obit
}
-define zeroext i1 @ssubo.i32(i32 %v1, i32 %v2, i32* %res) {
+define zeroext i1 @ssubo1.i32(i32 %v1, i32 %v2, i32* %res) {
entry:
-; CHECK-LABEL: ssubo.i32
+; CHECK-LABEL: ssubo1.i32
; CHECK: subs {{w[0-9]+}}, w0, w1
; CHECK-NEXT: cset {{w[0-9]+}}, vs
%t = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %v1, i32 %v2)
%val = extractvalue {i32, i1} %t, 0
%obit = extractvalue {i32, i1} %t, 1
store i32 %val, i32* %res
+ ret i1 %obit
+}
+
+define zeroext i1 @ssubo2.i32(i32 %v1, i32* %res) {
+entry:
+; CHECK-LABEL: ssubo2.i32
+; CHECK: adds {{w[0-9]+}}, w0, #4
+; CHECK-NEXT: cset {{w[0-9]+}}, vs
+ %t = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %v1, i32 -4)
+ %val = extractvalue {i32, i1} %t, 0
+ %obit = extractvalue {i32, i1} %t, 1
+ store i32 %val, i32* %res
ret i1 %obit
}
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