[PowerPC] Mark many instructions as commutative

I'm under the impression that we used to infer the isCommutable flag from the
instruction-associated pattern. Regardless, we don't seem to do this (at least
by default) any more. I've gone through all of our instruction definitions, and
marked as commutative all of those that should be trivial to commute (by
exchanging the first two operands). There has been special code for the RL*
instructions, and that's not changed.

Before this change, we had the following commutative instructions:

 RLDIMI
 RLDIMIo
 RLWIMI
 RLWIMI8
 RLWIMI8o
 RLWIMIo
 XSADDDP
 XSMULDP
 XVADDDP
 XVADDSP
 XVMULDP
 XVMULSP

After:

 ADD4
 ADD4o
 ADD8
 ADD8o
 ADDC
 ADDC8
 ADDC8o
 ADDCo
 ADDE
 ADDE8
 ADDE8o
 ADDEo
 AND
 AND8
 AND8o
 ANDo
 CRAND
 CREQV
 CRNAND
 CRNOR
 CROR
 CRXOR
 EQV
 EQV8
 EQV8o
 EQVo
 FADD
 FADDS
 FADDSo
 FADDo
 FMADD
 FMADDS
 FMADDSo
 FMADDo
 FMSUB
 FMSUBS
 FMSUBSo
 FMSUBo
 FMUL
 FMULS
 FMULSo
 FMULo
 FNMADD
 FNMADDS
 FNMADDSo
 FNMADDo
 FNMSUB
 FNMSUBS
 FNMSUBSo
 FNMSUBo
 MULHD
 MULHDU
 MULHDUo
 MULHDo
 MULHW
 MULHWU
 MULHWUo
 MULHWo
 MULLD
 MULLDo
 MULLW
 MULLWo
 NAND
 NAND8
 NAND8o
 NANDo
 NOR
 NOR8
 NOR8o
 NORo
 OR
 OR8
 OR8o
 ORo
 RLDIMI
 RLDIMIo
 RLWIMI
 RLWIMI8
 RLWIMI8o
 RLWIMIo
 VADDCUW
 VADDFP
 VADDSBS
 VADDSHS
 VADDSWS
 VADDUBM
 VADDUBS
 VADDUHM
 VADDUHS
 VADDUWM
 VADDUWS
 VAND
 VAVGSB
 VAVGSH
 VAVGSW
 VAVGUB
 VAVGUH
 VAVGUW
 VMADDFP
 VMAXFP
 VMAXSB
 VMAXSH
 VMAXSW
 VMAXUB
 VMAXUH
 VMAXUW
 VMHADDSHS
 VMHRADDSHS
 VMINFP
 VMINSB
 VMINSH
 VMINSW
 VMINUB
 VMINUH
 VMINUW
 VMLADDUHM
 VMULESB
 VMULESH
 VMULEUB
 VMULEUH
 VMULOSB
 VMULOSH
 VMULOUB
 VMULOUH
 VNMSUBFP
 VOR
 VXOR
 XOR
 XOR8
 XOR8o
 XORo
 XSADDDP
 XSMADDADP
 XSMAXDP
 XSMINDP
 XSMSUBADP
 XSMULDP
 XSNMADDADP
 XSNMSUBADP
 XVADDDP
 XVADDSP
 XVMADDADP
 XVMADDASP
 XVMAXDP
 XVMAXSP
 XVMINDP
 XVMINSP
 XVMSUBADP
 XVMSUBASP
 XVMULDP
 XVMULSP
 XVNMADDADP
 XVNMADDASP
 XVNMSUBADP
 XVNMSUBASP
 XXLAND
 XXLNOR
 XXLOR
 XXLXOR

This is a by-inspection change, and I'm not sure how to write a reliable test
case. I would like advice on this, however.

llvm-svn: 204609

4 files changed, 63 insertions, 4 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCInstr64Bit.td b/llvm/lib/Target/PowerPC/PPCInstr64Bit.td
index 50b210f41b5..b71c09ea8e1 100644
--- a/llvm/lib/Target/PowerPC/PPCInstr64Bit.td
+++ b/llvm/lib/Target/PowerPC/PPCInstr64Bit.td
@@ -376,30 +376,36 @@ def LIS8 : DForm_2_r0<15, (outs g8rc:$rD), (ins s17imm64:$imm),
 }
 
 // Logical ops.
+let isCommutable = 1 in {
 defm NAND8: XForm_6r<31, 476, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "nand", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (not (and i64:$rS, i64:$rB)))]>;
 defm AND8 : XForm_6r<31,  28, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "and", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (and i64:$rS, i64:$rB))]>;
+} // isCommutable
 defm ANDC8: XForm_6r<31,  60, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "andc", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (and i64:$rS, (not i64:$rB)))]>;
+let isCommutable = 1 in {
 defm OR8  : XForm_6r<31, 444, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "or", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (or i64:$rS, i64:$rB))]>;
 defm NOR8 : XForm_6r<31, 124, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "nor", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (not (or i64:$rS, i64:$rB)))]>;
+} // isCommutable
 defm ORC8 : XForm_6r<31, 412, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "orc", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (or i64:$rS, (not i64:$rB)))]>;
+let isCommutable = 1 in {
 defm EQV8 : XForm_6r<31, 284, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "eqv", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (not (xor i64:$rS, i64:$rB)))]>;
 defm XOR8 : XForm_6r<31, 316, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                      "xor", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i64:$rA, (xor i64:$rS, i64:$rB))]>;
+} // let isCommutable = 1
 
 // Logical ops with immediate.
 let Defs = [CR0] in {
@@ -425,6 +431,7 @@ def XORIS8  : DForm_4<27, (outs g8rc:$dst), (ins g8rc:$src1, u16imm64:$src2),
                       "xoris $dst, $src1, $src2", IIC_IntSimple,
                    [(set i64:$dst, (xor i64:$src1, imm16ShiftedZExt:$src2))]>;
 
+let isCommutable = 1 in
 defm ADD8  : XOForm_1r<31, 266, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                        "add", "$rT, $rA, $rB", IIC_IntSimple,
                        [(set i64:$rT, (add i64:$rA, i64:$rB))]>;
@@ -434,10 +441,12 @@ def ADD8TLS  : XOForm_1<31, 266, 0, (outs g8rc:$rT), (ins g8rc:$rA, tlsreg:$rB),
                         "add $rT, $rA, $rB", IIC_IntSimple,
                         [(set i64:$rT, (add i64:$rA, tglobaltlsaddr:$rB))]>;
                      
+let isCommutable = 1 in
 defm ADDC8 : XOForm_1rc<31, 10, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                         "addc", "$rT, $rA, $rB", IIC_IntGeneral,
                         [(set i64:$rT, (addc i64:$rA, i64:$rB))]>,
                         PPC970_DGroup_Cracked;
+
 let Defs = [CARRY] in
 def ADDIC8 : DForm_2<12, (outs g8rc:$rD), (ins g8rc:$rA, s16imm64:$imm),
                      "addic $rD, $rA, $imm", IIC_IntGeneral,
@@ -465,6 +474,7 @@ defm NEG8    : XOForm_3r<31, 104, 0, (outs g8rc:$rT), (ins g8rc:$rA),
                         "neg", "$rT, $rA", IIC_IntSimple,
                         [(set i64:$rT, (ineg i64:$rA))]>;
 let Uses = [CARRY] in {
+let isCommutable = 1 in
 defm ADDE8   : XOForm_1rc<31, 138, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                           "adde", "$rT, $rA, $rB", IIC_IntGeneral,
                           [(set i64:$rT, (adde i64:$rA, i64:$rB))]>;
@@ -493,12 +503,14 @@ let isAsmParserOnly = 1 in
 def ADD8TLS_ : XOForm_1<31, 266, 0, (outs g8rc:$rT), (ins g8rc:$rA, tlsreg:$rB),
                         "add $rT, $rA, $rB", IIC_IntSimple, []>;
 
+let isCommutable = 1 in {
 defm MULHD : XOForm_1r<31, 73, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                        "mulhd", "$rT, $rA, $rB", IIC_IntMulHW,
                        [(set i64:$rT, (mulhs i64:$rA, i64:$rB))]>;
 defm MULHDU : XOForm_1r<31, 9, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                        "mulhdu", "$rT, $rA, $rB", IIC_IntMulHWU,
                        [(set i64:$rT, (mulhu i64:$rA, i64:$rB))]>;
+} // isCommutable
 }
 } // Interpretation64Bit
 
@@ -575,6 +587,7 @@ defm DIVDU : XOForm_1r<31, 457, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                        "divdu", "$rT, $rA, $rB", IIC_IntDivD,
                        [(set i64:$rT, (udiv i64:$rA, i64:$rB))]>, isPPC64,
                        PPC970_DGroup_First, PPC970_DGroup_Cracked;
+let isCommutable = 1 in
 defm MULLD : XOForm_1r<31, 233, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                        "mulld", "$rT, $rA, $rB", IIC_IntMulHD,
                        [(set i64:$rT, (mul i64:$rA, i64:$rB))]>, isPPC64;
diff --git a/llvm/lib/Target/PowerPC/PPCInstrAltivec.td b/llvm/lib/Target/PowerPC/PPCInstrAltivec.td
index b67837394ae..2fd4a3eeae7 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrAltivec.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrAltivec.td
@@ -324,6 +324,7 @@ def STVXL : XForm_8<31, 487, (outs), (ins vrrc:$rS, memrr:$dst),
 
 let PPC970_Unit = 5 in {  // VALU Operations.
 // VA-Form instructions.  3-input AltiVec ops.
+let isCommutable = 1 in {
 def VMADDFP : VAForm_1<46, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vC, vrrc:$vB),
                        "vmaddfp $vD, $vA, $vC, $vB", IIC_VecFP,
                        [(set v4f32:$vD,
@@ -333,12 +334,13 @@ def VMADDFP : VAForm_1<46, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vC, vrrc:$vB),
 def VNMSUBFP: VAForm_1<47, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vC, vrrc:$vB),
                        "vnmsubfp $vD, $vA, $vC, $vB", IIC_VecFP,
                        [(set v4f32:$vD, (fneg (fma v4f32:$vA, v4f32:$vC,
-                                                  (fneg v4f32:$vB))))]>; 
+                                                  (fneg v4f32:$vB))))]>;
 
 def VMHADDSHS  : VA1a_Int_Ty<32, "vmhaddshs", int_ppc_altivec_vmhaddshs, v8i16>;
 def VMHRADDSHS : VA1a_Int_Ty<33, "vmhraddshs", int_ppc_altivec_vmhraddshs,
                              v8i16>;
 def VMLADDUHM  : VA1a_Int_Ty<34, "vmladduhm", int_ppc_altivec_vmladduhm, v8i16>;
+} // isCommutable
 
 def VPERM      : VA1a_Int_Ty3<43, "vperm", int_ppc_altivec_vperm,
                               v4i32, v4i32, v16i8>;
@@ -351,6 +353,7 @@ def VSLDOI  : VAForm_2<44, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB, u5imm:$SH),
                          (vsldoi_shuffle:$SH v16i8:$vA, v16i8:$vB))]>;
 
 // VX-Form instructions.  AltiVec arithmetic ops.
+let isCommutable = 1 in {
 def VADDFP : VXForm_1<10, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
                       "vaddfp $vD, $vA, $vB", IIC_VecFP,
                       [(set v4f32:$vD, (fadd v4f32:$vA, v4f32:$vB))]>;
@@ -372,8 +375,9 @@ def VADDSWS : VX1_Int_Ty<896, "vaddsws", int_ppc_altivec_vaddsws, v4i32>;
 def VADDUBS : VX1_Int_Ty<512, "vaddubs", int_ppc_altivec_vaddubs, v16i8>;
 def VADDUHS : VX1_Int_Ty<576, "vadduhs", int_ppc_altivec_vadduhs, v8i16>;
 def VADDUWS : VX1_Int_Ty<640, "vadduws", int_ppc_altivec_vadduws, v4i32>;
-                             
-                             
+} // isCommutable
+
+let isCommutable = 1 in
 def VAND : VXForm_1<1028, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
                     "vand $vD, $vA, $vB", IIC_VecFP,
                     [(set v4i32:$vD, (and v4i32:$vA, v4i32:$vB))]>;
@@ -423,6 +427,7 @@ def VCTSXS_0 : VXForm_1<970, (outs vrrc:$vD), (ins vrrc:$vB),
 def VEXPTEFP : VX2_Int_SP<394, "vexptefp", int_ppc_altivec_vexptefp>;
 def VLOGEFP  : VX2_Int_SP<458, "vlogefp",  int_ppc_altivec_vlogefp>;
 
+let isCommutable = 1 in {
 def VAVGSB : VX1_Int_Ty<1282, "vavgsb", int_ppc_altivec_vavgsb, v16i8>;
 def VAVGSH : VX1_Int_Ty<1346, "vavgsh", int_ppc_altivec_vavgsh, v8i16>;
 def VAVGSW : VX1_Int_Ty<1410, "vavgsw", int_ppc_altivec_vavgsw, v4i32>;
@@ -444,6 +449,7 @@ def VMINSW : VX1_Int_Ty< 898, "vminsw", int_ppc_altivec_vminsw, v4i32>;
 def VMINUB : VX1_Int_Ty< 514, "vminub", int_ppc_altivec_vminub, v16i8>;
 def VMINUH : VX1_Int_Ty< 578, "vminuh", int_ppc_altivec_vminuh, v8i16>;
 def VMINUW : VX1_Int_Ty< 642, "vminuw", int_ppc_altivec_vminuw, v4i32>;
+} // isCommutable
 
 def VMRGHB : VXForm_1< 12, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
                       "vmrghb $vD, $vA, $vB", IIC_VecFP,
@@ -477,6 +483,7 @@ def VMSUMUHM : VA1a_Int_Ty3<38, "vmsumuhm", int_ppc_altivec_vmsumuhm,
 def VMSUMUHS : VA1a_Int_Ty3<39, "vmsumuhs", int_ppc_altivec_vmsumuhs,
                             v4i32, v8i16, v4i32>;
 
+let isCommutable = 1 in {
 def VMULESB : VX1_Int_Ty2<776, "vmulesb", int_ppc_altivec_vmulesb,
                           v8i16, v16i8>;
 def VMULESH : VX1_Int_Ty2<840, "vmulesh", int_ppc_altivec_vmulesh,
@@ -493,6 +500,7 @@ def VMULOUB : VX1_Int_Ty2<  8, "vmuloub", int_ppc_altivec_vmuloub,
                           v8i16, v16i8>;
 def VMULOUH : VX1_Int_Ty2< 72, "vmulouh", int_ppc_altivec_vmulouh,
                           v4i32, v8i16>;
+} // isCommutable
                        
 def VREFP     : VX2_Int_SP<266, "vrefp",     int_ppc_altivec_vrefp>;
 def VRFIM     : VX2_Int_SP<714, "vrfim",     int_ppc_altivec_vrfim>;
@@ -537,12 +545,14 @@ def VNOR : VXForm_1<1284, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
                     "vnor $vD, $vA, $vB", IIC_VecFP,
                     [(set v4i32:$vD, (vnot_ppc (or v4i32:$vA,
                                                    v4i32:$vB)))]>;
+let isCommutable = 1 in {
 def VOR : VXForm_1<1156, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
                       "vor $vD, $vA, $vB", IIC_VecFP,
                       [(set v4i32:$vD, (or v4i32:$vA, v4i32:$vB))]>;
 def VXOR : VXForm_1<1220, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
                       "vxor $vD, $vA, $vB", IIC_VecFP,
                       [(set v4i32:$vD, (xor v4i32:$vA, v4i32:$vB))]>;
+} // isCommutable
 
 def VRLB   : VX1_Int_Ty<   4, "vrlb", int_ppc_altivec_vrlb, v16i8>;
 def VRLH   : VX1_Int_Ty<  68, "vrlh", int_ppc_altivec_vrlh, v8i16>;
diff --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.td b/llvm/lib/Target/PowerPC/PPCInstrInfo.td
index deb8b4617e0..1d984aba1fa 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.td
@@ -1731,30 +1731,36 @@ let isCompare = 1, neverHasSideEffects = 1 in {
 }
 
 let PPC970_Unit = 1, neverHasSideEffects = 1 in {  // FXU Operations.
+let isCommutable = 1 in {
 defm NAND : XForm_6r<31, 476, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "nand", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (not (and i32:$rS, i32:$rB)))]>;
 defm AND  : XForm_6r<31,  28, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "and", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (and i32:$rS, i32:$rB))]>;
+} // isCommutable
 defm ANDC : XForm_6r<31,  60, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "andc", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (and i32:$rS, (not i32:$rB)))]>;
+let isCommutable = 1 in {
 defm OR   : XForm_6r<31, 444, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "or", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (or i32:$rS, i32:$rB))]>;
 defm NOR  : XForm_6r<31, 124, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "nor", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (not (or i32:$rS, i32:$rB)))]>;
+} // isCommutable
 defm ORC  : XForm_6r<31, 412, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "orc", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (or i32:$rS, (not i32:$rB)))]>;
+let isCommutable = 1 in {
 defm EQV  : XForm_6r<31, 284, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "eqv", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (not (xor i32:$rS, i32:$rB)))]>;
 defm XOR  : XForm_6r<31, 316, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "xor", "$rA, $rS, $rB", IIC_IntSimple,
                      [(set i32:$rA, (xor i32:$rS, i32:$rB))]>;
+} // isCommutable
 defm SLW  : XForm_6r<31,  24, (outs gprc:$rA), (ins gprc:$rS, gprc:$rB),
                      "slw", "$rA, $rS, $rB", IIC_IntGeneral,
                      [(set i32:$rA, (PPCshl i32:$rS, i32:$rB))]>;
@@ -1918,6 +1924,7 @@ def MCRF   : XLForm_3<19, 0, (outs crrc:$BF), (ins crrc:$BFA),
                       "mcrf $BF, $BFA", IIC_BrMCR>,
              PPC970_DGroup_First, PPC970_Unit_CRU;
 
+let isCommutable = 1 in {
 def CRAND  : XLForm_1<19, 257, (outs crbitrc:$CRD),
                                (ins crbitrc:$CRA, crbitrc:$CRB),
                       "crand $CRD, $CRA, $CRB", IIC_BrCR,
@@ -1947,6 +1954,7 @@ def CREQV  : XLForm_1<19, 289, (outs crbitrc:$CRD),
                                (ins crbitrc:$CRA, crbitrc:$CRB),
                       "creqv $CRD, $CRA, $CRB", IIC_BrCR,
                       [(set i1:$CRD, (not (xor i1:$CRA, i1:$CRB)))]>;
+} // isCommutable
 
 def CRANDC : XLForm_1<19, 129, (outs crbitrc:$CRD),
                                (ins crbitrc:$CRA, crbitrc:$CRB),
@@ -2098,7 +2106,7 @@ let Uses = [RM] in {
 
 let PPC970_Unit = 1, neverHasSideEffects = 1 in {  // FXU Operations.
 // XO-Form instructions.  Arithmetic instructions that can set overflow bit
-//
+let isCommutable = 1 in
 defm ADD4  : XOForm_1r<31, 266, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                        "add", "$rT, $rA, $rB", IIC_IntSimple,
                        [(set i32:$rT, (add i32:$rA, i32:$rB))]>;
@@ -2106,10 +2114,12 @@ let isCodeGenOnly = 1 in
 def ADD4TLS  : XOForm_1<31, 266, 0, (outs gprc:$rT), (ins gprc:$rA, tlsreg32:$rB),
                        "add $rT, $rA, $rB", IIC_IntSimple,
                        [(set i32:$rT, (add i32:$rA, tglobaltlsaddr:$rB))]>;
+let isCommutable = 1 in
 defm ADDC  : XOForm_1rc<31, 10, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                         "addc", "$rT, $rA, $rB", IIC_IntGeneral,
                         [(set i32:$rT, (addc i32:$rA, i32:$rB))]>,
                         PPC970_DGroup_Cracked;
+
 defm DIVW  : XOForm_1r<31, 491, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                        "divw", "$rT, $rA, $rB", IIC_IntDivW,
                        [(set i32:$rT, (sdiv i32:$rA, i32:$rB))]>,
@@ -2118,6 +2128,7 @@ defm DIVWU : XOForm_1r<31, 459, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                        "divwu", "$rT, $rA, $rB", IIC_IntDivW,
                        [(set i32:$rT, (udiv i32:$rA, i32:$rB))]>,
                        PPC970_DGroup_First, PPC970_DGroup_Cracked;
+let isCommutable = 1 in {
 defm MULHW : XOForm_1r<31, 75, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                        "mulhw", "$rT, $rA, $rB", IIC_IntMulHW,
                        [(set i32:$rT, (mulhs i32:$rA, i32:$rB))]>;
@@ -2127,6 +2138,7 @@ defm MULHWU : XOForm_1r<31, 11, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
 defm MULLW : XOForm_1r<31, 235, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                        "mullw", "$rT, $rA, $rB", IIC_IntMulHW,
                        [(set i32:$rT, (mul i32:$rA, i32:$rB))]>;
+} // isCommutable
 defm SUBF  : XOForm_1r<31, 40, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                        "subf", "$rT, $rA, $rB", IIC_IntGeneral,
                        [(set i32:$rT, (sub i32:$rB, i32:$rA))]>;
@@ -2138,6 +2150,7 @@ defm NEG    : XOForm_3r<31, 104, 0, (outs gprc:$rT), (ins gprc:$rA),
                         "neg", "$rT, $rA", IIC_IntSimple,
                         [(set i32:$rT, (ineg i32:$rA))]>;
 let Uses = [CARRY] in {
+let isCommutable = 1 in
 defm ADDE  : XOForm_1rc<31, 138, 0, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
                         "adde", "$rT, $rA, $rB", IIC_IntGeneral,
                         [(set i32:$rT, (adde i32:$rA, i32:$rB))]>;
@@ -2164,6 +2177,7 @@ defm SUBFZE : XOForm_3rc<31, 200, 0, (outs gprc:$rT), (ins gprc:$rA),
 //
 let PPC970_Unit = 3, neverHasSideEffects = 1 in {  // FPU Operations.
 let Uses = [RM] in {
+let isCommutable = 1 in {
   defm FMADD : AForm_1r<63, 29, 
                       (outs f8rc:$FRT), (ins f8rc:$FRA, f8rc:$FRC, f8rc:$FRB),
                       "fmadd", "$FRT, $FRA, $FRC, $FRB", IIC_FPFused,
@@ -2202,6 +2216,7 @@ let Uses = [RM] in {
                       "fnmsubs", "$FRT, $FRA, $FRC, $FRB", IIC_FPGeneral,
                       [(set f32:$FRT, (fneg (fma f32:$FRA, f32:$FRC,
                                                  (fneg f32:$FRB))))]>;
+} // isCommutable
 }
 // FSEL is artificially split into 4 and 8-byte forms for the result.  To avoid
 // having 4 of these, force the comparison to always be an 8-byte double (code
@@ -2217,6 +2232,7 @@ defm FSELS : AForm_1r<63, 23,
                       "fsel", "$FRT, $FRA, $FRC, $FRB", IIC_FPGeneral,
                       [(set f32:$FRT, (PPCfsel f64:$FRA, f32:$FRC, f32:$FRB))]>;
 let Uses = [RM] in {
+  let isCommutable = 1 in {
   defm FADD  : AForm_2r<63, 21,
                         (outs f8rc:$FRT), (ins f8rc:$FRA, f8rc:$FRB),
                         "fadd", "$FRT, $FRA, $FRB", IIC_FPAddSub,
@@ -2225,6 +2241,7 @@ let Uses = [RM] in {
                         (outs f4rc:$FRT), (ins f4rc:$FRA, f4rc:$FRB),
                         "fadds", "$FRT, $FRA, $FRB", IIC_FPGeneral,
                         [(set f32:$FRT, (fadd f32:$FRA, f32:$FRB))]>;
+  } // isCommutable
   defm FDIV  : AForm_2r<63, 18,
                         (outs f8rc:$FRT), (ins f8rc:$FRA, f8rc:$FRB),
                         "fdiv", "$FRT, $FRA, $FRB", IIC_FPDivD,
@@ -2233,6 +2250,7 @@ let Uses = [RM] in {
                         (outs f4rc:$FRT), (ins f4rc:$FRA, f4rc:$FRB),
                         "fdivs", "$FRT, $FRA, $FRB", IIC_FPDivS,
                         [(set f32:$FRT, (fdiv f32:$FRA, f32:$FRB))]>;
+  let isCommutable = 1 in {
   defm FMUL  : AForm_3r<63, 25,
                         (outs f8rc:$FRT), (ins f8rc:$FRA, f8rc:$FRC),
                         "fmul", "$FRT, $FRA, $FRC", IIC_FPFused,
@@ -2241,6 +2259,7 @@ let Uses = [RM] in {
                         (outs f4rc:$FRT), (ins f4rc:$FRA, f4rc:$FRC),
                         "fmuls", "$FRT, $FRA, $FRC", IIC_FPGeneral,
                         [(set f32:$FRT, (fmul f32:$FRA, f32:$FRC))]>;
+  } // isCommutable
   defm FSUB  : AForm_2r<63, 20,
                         (outs f8rc:$FRT), (ins f8rc:$FRA, f8rc:$FRB),
                         "fsub", "$FRT, $FRA, $FRB", IIC_FPAddSub,
diff --git a/llvm/lib/Target/PowerPC/PPCInstrVSX.td b/llvm/lib/Target/PowerPC/PPCInstrVSX.td
index 63ea15db710..aee377b46f0 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrVSX.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrVSX.td
@@ -127,6 +127,7 @@ let Uses = [RM] in {
                         [(set v4f32:$XT, (fsub v4f32:$XA, v4f32:$XB))]>;
 
   // FMA Instructions
+  let isCommutable = 1 in
   def XSMADDADP : XX3Form<60, 33,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xsmaddadp $XT, $XA, $XB", IIC_VecFP,
@@ -140,6 +141,7 @@ let Uses = [RM] in {
   // no further uses. We probably want to do this after scheduling but before
   // register allocation.
 
+  let isCommutable = 1 in
   def XSMSUBADP : XX3Form<60, 49,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xsmsubadp $XT, $XA, $XB", IIC_VecFP,
@@ -150,6 +152,7 @@ let Uses = [RM] in {
                           "xsmsubmdp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XSNMADDADP : XX3Form<60, 161,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xsnmaddadp $XT, $XA, $XB", IIC_VecFP,
@@ -160,6 +163,7 @@ let Uses = [RM] in {
                           "xsnmaddmdp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XSNMSUBADP : XX3Form<60, 177,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xsnmsubadp $XT, $XA, $XB", IIC_VecFP,
@@ -170,6 +174,7 @@ let Uses = [RM] in {
                           "xsnmsubmdp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVMADDADP : XX3Form<60, 97,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvmaddadp $XT, $XA, $XB", IIC_VecFP,
@@ -180,6 +185,7 @@ let Uses = [RM] in {
                           "xvmaddmdp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVMADDASP : XX3Form<60, 65,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvmaddasp $XT, $XA, $XB", IIC_VecFP,
@@ -190,6 +196,7 @@ let Uses = [RM] in {
                           "xvmaddmsp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVMSUBADP : XX3Form<60, 113,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvmsubadp $XT, $XA, $XB", IIC_VecFP,
@@ -200,6 +207,7 @@ let Uses = [RM] in {
                           "xvmsubmdp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVMSUBASP : XX3Form<60, 81,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvmsubasp $XT, $XA, $XB", IIC_VecFP,
@@ -210,6 +218,7 @@ let Uses = [RM] in {
                           "xvmsubmsp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVNMADDADP : XX3Form<60, 225,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvnmaddadp $XT, $XA, $XB", IIC_VecFP,
@@ -220,6 +229,7 @@ let Uses = [RM] in {
                           "xvnmaddmdp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVNMADDASP : XX3Form<60, 193,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvnmaddasp $XT, $XA, $XB", IIC_VecFP,
@@ -230,6 +240,7 @@ let Uses = [RM] in {
                           "xvnmaddmsp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVNMSUBADP : XX3Form<60, 241,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvnmsubadp $XT, $XA, $XB", IIC_VecFP,
@@ -240,6 +251,7 @@ let Uses = [RM] in {
                           "xvnmsubmdp $XT, $XA, $XB", IIC_VecFP, []>,
                           RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">;
 
+  let isCommutable = 1 in
   def XVNMSUBASP : XX3Form<60, 209,
                           (outs vsrc:$XT), (ins vsrc:$XTi, vsrc:$XA, vsrc:$XB),
                           "xvnmsubasp $XT, $XA, $XB", IIC_VecFP,
@@ -561,6 +573,7 @@ let Uses = [RM] in {
                       [(set v4f32:$XT, (ftrunc v4f32:$XB))]>;
 
   // Max/Min Instructions
+  let isCommutable = 1 in {
   def XSMAXDP : XX3Form<60, 160,
                         (outs vsrc:$XT), (ins vsrc:$XA, vsrc:$XB),
                         "xsmaxdp $XT, $XA, $XB", IIC_VecFP, []>;
@@ -581,15 +594,18 @@ let Uses = [RM] in {
   def XVMINSP : XX3Form<60, 200,
                         (outs vsrc:$XT), (ins vsrc:$XA, vsrc:$XB),
                         "xvminsp $XT, $XA, $XB", IIC_VecFP, []>;
+  } // isCommutable
 } // Uses = [RM]
 
   // Logical Instructions
+  let isCommutable = 1 in
   def XXLAND : XX3Form<60, 130,
                        (outs vsrc:$XT), (ins vsrc:$XA, vsrc:$XB),
                        "xxland $XT, $XA, $XB", IIC_VecGeneral, []>;
   def XXLANDC : XX3Form<60, 138,
                         (outs vsrc:$XT), (ins vsrc:$XA, vsrc:$XB),
                         "xxlandc $XT, $XA, $XB", IIC_VecGeneral, []>;
+  let isCommutable = 1 in {
   def XXLNOR : XX3Form<60, 162,
                        (outs vsrc:$XT), (ins vsrc:$XA, vsrc:$XB),
                        "xxlnor $XT, $XA, $XB", IIC_VecGeneral, []>;
@@ -599,6 +615,7 @@ let Uses = [RM] in {
   def XXLXOR : XX3Form<60, 154,
                        (outs vsrc:$XT), (ins vsrc:$XA, vsrc:$XB),
                        "xxlxor $XT, $XA, $XB", IIC_VecGeneral, []>;
+  } // isCommutable
 
   // Permutation Instructions
   def XXMRGHW : XX3Form<60, 18,