[llvm] r322373 - [PowerPC] Don't miscompile rotate+mask into an ANDIo if it can't recreate the immediate
Benjamin Kramer via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 12 07:03:24 PST 2018
Author: d0k
Date: Fri Jan 12 07:03:24 2018
New Revision: 322373
URL: http://llvm.org/viewvc/llvm-project?rev=322373&view=rev
Log:
[PowerPC] Don't miscompile rotate+mask into an ANDIo if it can't recreate the immediate
I'm not even sure if this transform is ever worth it, but this at least
stops the bleeding.
Modified:
llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
llvm/trunk/test/CodeGen/PowerPC/convert-rr-to-ri-instrs.mir
Modified: llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp?rev=322373&r1=322372&r2=322373&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp Fri Jan 12 07:03:24 2018
@@ -2444,6 +2444,8 @@ bool PPCInstrInfo::convertToImmediateFor
Is64BitLI = Opc != PPC::RLDICL_32;
NewImm = InVal.getSExtValue();
SetCR = Opc == PPC::RLDICLo;
+ if (SetCR && (SExtImm & NewImm) != NewImm)
+ return false;
break;
}
return false;
@@ -2471,6 +2473,8 @@ bool PPCInstrInfo::convertToImmediateFor
Is64BitLI = Opc == PPC::RLWINM8 || Opc == PPC::RLWINM8o;
NewImm = InVal.getSExtValue();
SetCR = Opc == PPC::RLWINMo || Opc == PPC::RLWINM8o;
+ if (SetCR && (SExtImm & NewImm) != NewImm)
+ return false;
break;
}
return false;
Modified: llvm/trunk/test/CodeGen/PowerPC/convert-rr-to-ri-instrs.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/convert-rr-to-ri-instrs.mir?rev=322373&r1=322372&r2=322373&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/convert-rr-to-ri-instrs.mir (original)
+++ llvm/trunk/test/CodeGen/PowerPC/convert-rr-to-ri-instrs.mir Fri Jan 12 07:03:24 2018
@@ -561,6 +561,16 @@
}
; Function Attrs: norecurse nounwind readnone
+ define i64 @testRLDICLo2(i64 %a, i64 %b) local_unnamed_addr #0 {
+ entry:
+ %shr = lshr i64 %a, 11
+ %and = and i64 %shr, 16777215
+ %tobool = icmp eq i64 %and, 0
+ %cond = select i1 %tobool, i64 %b, i64 %and
+ ret i64 %cond
+ }
+
+ ; Function Attrs: norecurse nounwind readnone
define zeroext i32 @testRLWINM(i32 zeroext %a) local_unnamed_addr #0 {
entry:
%shl = shl i32 %a, 4
@@ -602,6 +612,15 @@
}
; Function Attrs: norecurse nounwind readnone
+ define zeroext i32 @testRLWINMo2(i32 zeroext %a, i32 zeroext %b) local_unnamed_addr #0 {
+ entry:
+ %and = and i32 %a, 255
+ %tobool = icmp eq i32 %and, 0
+ %cond = select i1 %tobool, i32 %b, i32 %a
+ ret i32 %cond
+ }
+
+ ; Function Attrs: norecurse nounwind readnone
define i64 @testRLWINM8o(i64 %a, i64 %b) local_unnamed_addr #0 {
entry:
%a.tr = trunc i64 %a to i32
@@ -3904,6 +3923,59 @@ body: |
...
---
+name: testRLDICLo2
+# CHECK-ALL: name: testRLDICLo2
+alignment: 4
+exposesReturnsTwice: false
+legalized: false
+regBankSelected: false
+selected: false
+tracksRegLiveness: true
+registers:
+ - { id: 0, class: g8rc, preferred-register: '' }
+ - { id: 1, class: g8rc_and_g8rc_nox0, preferred-register: '' }
+ - { id: 2, class: g8rc_and_g8rc_nox0, preferred-register: '' }
+ - { id: 3, class: crrc, preferred-register: '' }
+ - { id: 4, class: g8rc, preferred-register: '' }
+liveins:
+ - { reg: '%x3', virtual-reg: '%0' }
+ - { reg: '%x4', virtual-reg: '%1' }
+frameInfo:
+ isFrameAddressTaken: false
+ isReturnAddressTaken: false
+ hasStackMap: false
+ hasPatchPoint: false
+ stackSize: 0
+ offsetAdjustment: 0
+ maxAlignment: 0
+ adjustsStack: false
+ hasCalls: false
+ stackProtector: ''
+ maxCallFrameSize: 4294967295
+ hasOpaqueSPAdjustment: false
+ hasVAStart: false
+ hasMustTailInVarArgFunc: false
+ savePoint: ''
+ restorePoint: ''
+fixedStack:
+stack:
+constants:
+body: |
+ bb.0.entry:
+ liveins: %x3, %x4
+
+ %1 = COPY %x4
+ %0 = LI8 200
+ %2 = RLDICLo %0, 61, 3, implicit-def %cr0
+ ; CHECK-NOT: ANDI
+ ; CHECK-LATE-NOT: andi.
+ %3 = COPY killed %cr0
+ %4 = ISEL8 %1, %2, %3.sub_eq
+ %x3 = COPY %4
+ BLR8 implicit %lr8, implicit %rm, implicit %x3
+
+...
+---
name: testRLWINM
# CHECK-ALL: name: testRLWINM
alignment: 4
@@ -4163,6 +4235,69 @@ body: |
%5 = COPY killed %cr0
%6 = ISEL %2, %3, %5.sub_eq
%8 = IMPLICIT_DEF
+ %7 = INSERT_SUBREG %8, killed %6, 1
+ %9 = RLDICL killed %7, 0, 32
+ %x3 = COPY %9
+ BLR8 implicit %lr8, implicit %rm, implicit %x3
+
+...
+---
+name: testRLWINMo2
+# CHECK-ALL: name: testRLWINMo2
+alignment: 4
+exposesReturnsTwice: false
+legalized: false
+regBankSelected: false
+selected: false
+tracksRegLiveness: true
+registers:
+ - { id: 0, class: g8rc, preferred-register: '' }
+ - { id: 1, class: g8rc, preferred-register: '' }
+ - { id: 2, class: gprc_and_gprc_nor0, preferred-register: '' }
+ - { id: 3, class: gprc_and_gprc_nor0, preferred-register: '' }
+ - { id: 4, class: gprc, preferred-register: '' }
+ - { id: 5, class: crrc, preferred-register: '' }
+ - { id: 6, class: gprc, preferred-register: '' }
+ - { id: 7, class: g8rc, preferred-register: '' }
+ - { id: 8, class: g8rc, preferred-register: '' }
+ - { id: 9, class: g8rc, preferred-register: '' }
+liveins:
+ - { reg: '%x3', virtual-reg: '%0' }
+ - { reg: '%x4', virtual-reg: '%1' }
+frameInfo:
+ isFrameAddressTaken: false
+ isReturnAddressTaken: false
+ hasStackMap: false
+ hasPatchPoint: false
+ stackSize: 0
+ offsetAdjustment: 0
+ maxAlignment: 0
+ adjustsStack: false
+ hasCalls: false
+ stackProtector: ''
+ maxCallFrameSize: 4294967295
+ hasOpaqueSPAdjustment: false
+ hasVAStart: false
+ hasMustTailInVarArgFunc: false
+ savePoint: ''
+ restorePoint: ''
+fixedStack:
+stack:
+constants:
+body: |
+ bb.0.entry:
+ liveins: %x3, %x4
+
+ %1 = COPY %x4
+ %0 = COPY %x3
+ %2 = COPY %1.sub_32
+ %3 = LI -22
+ %4 = RLWINMo %3, 5, 24, 31, implicit-def %cr0
+ ; CHECK-NOT: ANDI
+ ; CHECK-LATE-NOT: andi.
+ %5 = COPY killed %cr0
+ %6 = ISEL %2, %3, %5.sub_eq
+ %8 = IMPLICIT_DEF
%7 = INSERT_SUBREG %8, killed %6, 1
%9 = RLDICL killed %7, 0, 32
%x3 = COPY %9
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