[llvm] r323548 - [Hexagon] Fix an incorrect assertion in HexagonConstExtenders
Krzysztof Parzyszek via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 26 11:20:50 PST 2018
Author: kparzysz
Date: Fri Jan 26 11:20:50 2018
New Revision: 323548
URL: http://llvm.org/viewvc/llvm-project?rev=323548&view=rev
Log:
[Hexagon] Fix an incorrect assertion in HexagonConstExtenders
Added:
llvm/trunk/test/CodeGen/Hexagon/cext-opt-range-assert.mir
Modified:
llvm/trunk/lib/Target/Hexagon/HexagonConstExtenders.cpp
Modified: llvm/trunk/lib/Target/Hexagon/HexagonConstExtenders.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonConstExtenders.cpp?rev=323548&r1=323547&r2=323548&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonConstExtenders.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonConstExtenders.cpp Fri Jan 26 11:20:50 2018
@@ -999,15 +999,19 @@ unsigned HCE::getDirectRegReplacement(un
return 0;
}
-// Return the allowable deviation from the current value of Rb which the
+// Return the allowable deviation from the current value of Rb (i.e. the
+// range of values that can be added to the current value) which the
// instruction MI can accommodate.
// The instruction MI is a user of register Rb, which is defined via an
// extender. It may be possible for MI to be tweaked to work for a register
// defined with a slightly different value. For example
-// ... = L2_loadrub_io Rb, 0
+// ... = L2_loadrub_io Rb, 1
// can be modifed to be
-// ... = L2_loadrub_io Rb', 1
-// if Rb' = Rb-1.
+// ... = L2_loadrub_io Rb', 0
+// if Rb' = Rb+1.
+// The range for Rb would be [Min+1, Max+1], where [Min, Max] is a range
+// for L2_loadrub with offset 0. That means that Rb could be replaced with
+// Rc, where Rc-Rb belongs to [Min+1, Max+1].
OffsetRange HCE::getOffsetRange(Register Rb, const MachineInstr &MI) const {
unsigned Opc = MI.getOpcode();
// Instructions that are constant-extended may be replaced with something
@@ -1618,7 +1622,7 @@ bool HCE::replaceInstrExpr(const ExtDesc
assert(IdxOpc == Hexagon::A2_addi);
// Clamp Diff to the 16 bit range.
- int32_t D = isInt<16>(Diff) ? Diff : (Diff > 32767 ? 32767 : -32767);
+ int32_t D = isInt<16>(Diff) ? Diff : (Diff > 0 ? 32767 : -32768);
BuildMI(MBB, At, dl, HII->get(IdxOpc))
.add(MI.getOperand(0))
.add(MachineOperand(ExtR))
@@ -1626,11 +1630,13 @@ bool HCE::replaceInstrExpr(const ExtDesc
Diff -= D;
#ifndef NDEBUG
// Make sure the output is within allowable range for uses.
+ // "Diff" is a difference in the "opposite direction", i.e. Ext - DefV,
+ // not DefV - Ext, as the getOffsetRange would calculate.
OffsetRange Uses = getOffsetRange(MI.getOperand(0));
- if (!Uses.contains(Diff))
- dbgs() << "Diff: " << Diff << " out of range " << Uses
+ if (!Uses.contains(-Diff))
+ dbgs() << "Diff: " << -Diff << " out of range " << Uses
<< " for " << MI;
- assert(Uses.contains(Diff));
+ assert(Uses.contains(-Diff));
#endif
MBB.erase(MI);
return true;
Added: llvm/trunk/test/CodeGen/Hexagon/cext-opt-range-assert.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Hexagon/cext-opt-range-assert.mir?rev=323548&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Hexagon/cext-opt-range-assert.mir (added)
+++ llvm/trunk/test/CodeGen/Hexagon/cext-opt-range-assert.mir Fri Jan 26 11:20:50 2018
@@ -0,0 +1,54 @@
+# RUN: llc -march=hexagon -run-pass hexagon-cext-opt %s -o - | FileCheck %s
+# REQUIRES: asserts
+#
+# This testcase used to trigger an incorrect assertion. Make sure it no
+# longer does.
+# CHECK: A2_tfrsi @G + 65536
+
+--- |
+ define void @fred() {
+ ret void
+ }
+ @G = external global [128 x i16], align 8
+...
+
+---
+name: fred
+tracksRegLiveness: true
+
+body: |
+ bb.0:
+ successors: %bb.1
+ %6:intregs = A2_tfrsi @G
+ %7:intregs = A2_addi killed %6, 2
+ %8:intregs = A2_tfrsi 127
+ ADJCALLSTACKDOWN 0, 0, implicit-def %r29, implicit-def dead %r30, implicit %r31, implicit %r30, implicit %r29
+ %r0 = COPY %7
+ %r1 = COPY %8
+ %9:intregs = IMPLICIT_DEF
+ J2_callr killed %9, implicit-def dead %pc, implicit-def dead %r31, implicit %r29, implicit %r0, implicit %r1, implicit-def %r29
+ ADJCALLSTACKUP 0, 0, implicit-def dead %r29, implicit-def dead %r30, implicit-def dead %r31, implicit %r29
+ %5:intregs = A2_tfrsi 8
+ %10:intregs = A2_tfrsi @G + 8
+ %4:intregs = A2_addi killed %10, 2
+
+ bb.1:
+ successors: %bb.1, %bb.2
+ %0:intregs = PHI %4, %bb.0, %3, %bb.1
+ %1:intregs = PHI %5, %bb.0, %2, %bb.1
+ %11:predregs = C2_cmpgtui %1, 127
+ %2:intregs = A2_addi %1, 8
+ %3:intregs = A2_addi %0, 16
+ J2_jumpf %11, %bb.1, implicit-def %pc
+
+ bb.2:
+ %13:intregs = A2_tfrsi @G
+ %14:intregs = A2_addi killed %13, 2
+ %15:intregs = A2_tfrsi 127
+ ADJCALLSTACKDOWN 0, 0, implicit-def %r29, implicit-def dead %r30, implicit %r31, implicit %r30, implicit %r29
+ %r0 = COPY %14
+ %r1 = COPY %15
+ %16:intregs = IMPLICIT_DEF
+ PS_callr_nr killed %16, implicit %r0, implicit %r1, implicit-def %r29
+ ADJCALLSTACKUP 0, 0, implicit-def dead %r29, implicit-def dead %r30, implicit-def dead %r31, implicit %r29
+...
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