From: Hal Finkel <hfinkel@anl.gov>
Date: Wed, 11 Mar 2015 23:28:38 +0000 (+0000)
Subject: [PowerPC] Remove canFoldAsLoad from instruction definitions
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5127011d3ae68808df9e2bd4881ca0f20645b519;p=oota-llvm.git

[PowerPC] Remove canFoldAsLoad from instruction definitions

The PowerPC backend had a number of loads that were marked as canFoldAsLoad
(and I'm partially at fault here for copying around the relevant line of
TableGen definitions without really looking at what it meant). This is not
right; PPC (non-memory) instructions don't support direct memory operands, and
so there is nothing a 'foldable' instruction could be folded into.

Noticed by inspection, no test case.

The one thing we might lose by doing this is ability to fold some loads into
stackmap/patchpoint pseudo-instructions. However, this was untested, and would
not obviously have worked for extending loads, and I'd rather re-add support
for that once it can be tested.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231982 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/PowerPC/PPCInstr64Bit.td b/lib/Target/PowerPC/PPCInstr64Bit.td
index 76fa45c8183..36479e2ff41 100644
--- a/lib/Target/PowerPC/PPCInstr64Bit.td
+++ b/lib/Target/PowerPC/PPCInstr64Bit.td
@@ -700,7 +700,7 @@ def ISEL8   : AForm_4<31, 15,
 
 
 // Sign extending loads.
-let canFoldAsLoad = 1, PPC970_Unit = 2 in {
+let PPC970_Unit = 2 in {
 let Interpretation64Bit = 1, isCodeGenOnly = 1 in
 def LHA8: DForm_1<42, (outs g8rc:$rD), (ins memri:$src),
                   "lha $rD, $src", IIC_LdStLHA,
@@ -756,7 +756,7 @@ def LWAUX : XForm_1<31, 373, (outs g8rc:$rD, ptr_rc_nor0:$ea_result),
 
 let Interpretation64Bit = 1, isCodeGenOnly = 1 in {
 // Zero extending loads.
-let canFoldAsLoad = 1, PPC970_Unit = 2 in {
+let PPC970_Unit = 2 in {
 def LBZ8 : DForm_1<34, (outs g8rc:$rD), (ins memri:$src),
                   "lbz $rD, $src", IIC_LdStLoad,
                   [(set i64:$rD, (zextloadi8 iaddr:$src))]>;
@@ -814,7 +814,7 @@ def LWZUX8 : XForm_1<31, 55, (outs g8rc:$rD, ptr_rc_nor0:$ea_result),
 
 
 // Full 8-byte loads.
-let canFoldAsLoad = 1, PPC970_Unit = 2 in {
+let PPC970_Unit = 2 in {
 def LD   : DSForm_1<58, 0, (outs g8rc:$rD), (ins memrix:$src),
                     "ld $rD, $src", IIC_LdStLD,
                     [(set i64:$rD, (aligned4load ixaddr:$src))]>, isPPC64;
diff --git a/lib/Target/PowerPC/PPCInstrAltivec.td b/lib/Target/PowerPC/PPCInstrAltivec.td
index 30cee121ed5..2d04d81a2b5 100644
--- a/lib/Target/PowerPC/PPCInstrAltivec.td
+++ b/lib/Target/PowerPC/PPCInstrAltivec.td
@@ -352,7 +352,7 @@ def MTVSCR : VXForm_5<1604, (outs), (ins vrrc:$vB),
                       "mtvscr $vB", IIC_LdStLoad,
                       [(int_ppc_altivec_mtvscr v4i32:$vB)]>; 
 
-let canFoldAsLoad = 1, PPC970_Unit = 2 in {  // Loads.
+let PPC970_Unit = 2 in {  // Loads.
 def LVEBX: XForm_1<31,   7, (outs vrrc:$vD), (ins memrr:$src),
                    "lvebx $vD, $src", IIC_LdStLoad,
                    [(set v16i8:$vD, (int_ppc_altivec_lvebx xoaddr:$src))]>;
diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td
index be704482317..17e7eb39305 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/lib/Target/PowerPC/PPCInstrInfo.td
@@ -1498,7 +1498,7 @@ def TD : XForm_1<31, 68, (outs), (ins u5imm:$to, g8rc:$rA, g8rc:$rB),
 //
 
 // Unindexed (r+i) Loads. 
-let canFoldAsLoad = 1, PPC970_Unit = 2 in {
+let PPC970_Unit = 2 in {
 def LBZ : DForm_1<34, (outs gprc:$rD), (ins memri:$src),
                   "lbz $rD, $src", IIC_LdStLoad,
                   [(set i32:$rD, (zextloadi8 iaddr:$src))]>;
@@ -1595,7 +1595,7 @@ def LFDUX : XForm_1<31, 631, (outs f8rc:$rD, ptr_rc_nor0:$ea_result),
 
 // Indexed (r+r) Loads.
 //
-let canFoldAsLoad = 1, PPC970_Unit = 2 in {
+let PPC970_Unit = 2 in {
 def LBZX : XForm_1<31,  87, (outs gprc:$rD), (ins memrr:$src),
                    "lbzx $rD, $src", IIC_LdStLoad,
                    [(set i32:$rD, (zextloadi8 xaddr:$src))]>;
diff --git a/lib/Target/PowerPC/PPCInstrQPX.td b/lib/Target/PowerPC/PPCInstrQPX.td
index c984d461d25..5c66b42690c 100644
--- a/lib/Target/PowerPC/PPCInstrQPX.td
+++ b/lib/Target/PowerPC/PPCInstrQPX.td
@@ -501,7 +501,7 @@ let Uses = [RM] in {
                       "qvflogical $FRT, $FRA, $FRB, $tttt", IIC_VecPerm, []>;
 
   // Load indexed instructions
-  let mayLoad = 1, canFoldAsLoad = 1 in {
+  let mayLoad = 1 in {
     def QVLFDX : XForm_1<31, 583,
                         (outs qfrc:$FRT), (ins memrr:$src),
                         "qvlfdx $FRT, $src", IIC_LdStLFD,
diff --git a/lib/Target/PowerPC/PPCInstrVSX.td b/lib/Target/PowerPC/PPCInstrVSX.td
index d6cb3a0ea43..ec04da42a5b 100644
--- a/lib/Target/PowerPC/PPCInstrVSX.td
+++ b/lib/Target/PowerPC/PPCInstrVSX.td
@@ -66,7 +66,7 @@ let hasSideEffects = 0 in { // VSX instructions don't have side effects.
 let Uses = [RM] in {
 
   // Load indexed instructions
-  let mayLoad = 1, canFoldAsLoad = 1 in {
+  let mayLoad = 1 in {
     def LXSDX : XX1Form<31, 588,
                         (outs vsfrc:$XT), (ins memrr:$src),
                         "lxsdx $XT, $src", IIC_LdStLFD,