[llvm] r177294 - Cleanup initial-value constants in PPCCTRLoops
Hal Finkel
hfinkel at anl.gov
Mon Mar 18 10:40:27 PDT 2013
Author: hfinkel
Date: Mon Mar 18 12:40:27 2013
New Revision: 177294
URL: http://llvm.org/viewvc/llvm-project?rev=177294&view=rev
Log:
Cleanup initial-value constants in PPCCTRLoops
Because the initial-value constants had not been added to the list
of instructions considered for DCE the resulting code had redundant
constant-materialization instructions.
Added:
llvm/trunk/test/CodeGen/PowerPC/ctr-cleanup.ll
Modified:
llvm/trunk/lib/Target/PowerPC/PPCCTRLoops.cpp
Modified: llvm/trunk/lib/Target/PowerPC/PPCCTRLoops.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCCTRLoops.cpp?rev=177294&r1=177293&r2=177294&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCCTRLoops.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCCTRLoops.cpp Mon Mar 18 12:40:27 2013
@@ -380,13 +380,13 @@ CountValue *PPCCTRLoops::getTripCount(Ma
assert(InitialValue->isReg() && "Expecting register for init value");
unsigned InitialValueReg = InitialValue->getReg();
- const MachineInstr *DefInstr = MRI->getVRegDef(InitialValueReg);
+ MachineInstr *DefInstr = MRI->getVRegDef(InitialValueReg);
// Here we need to look for an immediate load (an li or lis/ori pair).
if (DefInstr && (DefInstr->getOpcode() == PPC::ORI8 ||
DefInstr->getOpcode() == PPC::ORI)) {
int64_t start = (short) DefInstr->getOperand(2).getImm();
- const MachineInstr *DefInstr2 =
+ MachineInstr *DefInstr2 =
MRI->getVRegDef(DefInstr->getOperand(0).getReg());
if (DefInstr2 && (DefInstr2->getOpcode() == PPC::LIS8 ||
DefInstr2->getOpcode() == PPC::LIS)) {
@@ -399,6 +399,10 @@ CountValue *PPCCTRLoops::getTripCount(Ma
if ((count % iv_value) != 0) {
return 0;
}
+
+ OldInsts.push_back(DefInstr);
+ OldInsts.push_back(DefInstr2);
+
return new CountValue(count/iv_value);
}
} else if (DefInstr && (DefInstr->getOpcode() == PPC::LI8 ||
@@ -409,6 +413,9 @@ CountValue *PPCCTRLoops::getTripCount(Ma
if ((count % iv_value) != 0) {
return 0;
}
+
+ OldInsts.push_back(DefInstr);
+
return new CountValue(count/iv_value);
} else if (iv_value == 1 || iv_value == -1) {
// We can't determine a constant starting value.
Added: llvm/trunk/test/CodeGen/PowerPC/ctr-cleanup.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/ctr-cleanup.ll?rev=177294&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/ctr-cleanup.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/ctr-cleanup.ll Mon Mar 18 12:40:27 2013
@@ -0,0 +1,25 @@
+; RUN: llc < %s -mcpu=a2 | FileCheck %s
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+define void @main() #0 {
+entry:
+ br i1 undef, label %for.end, label %for.body
+
+for.body: ; preds = %for.body, %entry
+ %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 1, %entry ]
+ %indvars.iv.next = add i64 %indvars.iv, 1
+ %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+ %exitcond = icmp eq i32 %lftr.wideiv, 5
+ br i1 %exitcond, label %for.end, label %for.body
+
+; CHECK: @main
+; CHECK: li {{[0-9]+}}, 4
+; CHECK-NOT: li {{[0-9]+}}, 4
+; CHECK: bdnz
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
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