[llvm-commits] [llvm] r70421 - in /llvm/trunk: lib/Analysis/ScalarEvolution.cpp test/Analysis/ScalarEvolution/sext-iv-0.ll test/Analysis/ScalarEvolution/sext-iv-1.ll
Dan Gohman
gohman at apple.com
Wed Apr 29 15:28:28 PDT 2009
Author: djg
Date: Wed Apr 29 17:28:28 2009
New Revision: 70421
URL: http://llvm.org/viewvc/llvm-project?rev=70421&view=rev
Log:
Generalize the cast-of-addrec folding to handle folding of SCEVs like
(sext i8 {-128,+,1} to i64) to i64 {-128,+,1}, where the iteration
crosses from negative to positive, but is still safe if the trip
count is within range.
Added:
llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-0.ll
llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-1.ll
Modified:
llvm/trunk/lib/Analysis/ScalarEvolution.cpp
Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=70421&r1=70420&r2=70421&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Wed Apr 29 17:28:28 2009
@@ -718,7 +718,7 @@
SCEVHandle BECount = getBackedgeTakenCount(AR->getLoop());
if (!isa<SCEVCouldNotCompute>(BECount)) {
// Manually compute the final value for AR, checking for
- // overflow at each step.
+ // overflow.
SCEVHandle Start = AR->getStart();
SCEVHandle Step = AR->getStepRecurrence(*this);
@@ -730,41 +730,34 @@
getTruncateOrZeroExtend(CastedBECount, BECount->getType())) {
const Type *WideTy =
IntegerType::get(getTypeSizeInBits(Start->getType()) * 2);
+ // Check whether Start+Step*BECount has no unsigned overflow.
SCEVHandle ZMul =
getMulExpr(CastedBECount,
getTruncateOrZeroExtend(Step, Start->getType()));
- // Check whether Start+Step*BECount has no unsigned overflow.
- if (getZeroExtendExpr(ZMul, WideTy) ==
- getMulExpr(getZeroExtendExpr(CastedBECount, WideTy),
- getZeroExtendExpr(Step, WideTy))) {
- SCEVHandle Add = getAddExpr(Start, ZMul);
- if (getZeroExtendExpr(Add, WideTy) ==
- getAddExpr(getZeroExtendExpr(Start, WideTy),
- getZeroExtendExpr(ZMul, WideTy)))
- // Return the expression with the addrec on the outside.
- return getAddRecExpr(getZeroExtendExpr(Start, Ty),
- getZeroExtendExpr(Step, Ty),
- AR->getLoop());
- }
+ SCEVHandle Add = getAddExpr(Start, ZMul);
+ if (getZeroExtendExpr(Add, WideTy) ==
+ getAddExpr(getZeroExtendExpr(Start, WideTy),
+ getMulExpr(getZeroExtendExpr(CastedBECount, WideTy),
+ getZeroExtendExpr(Step, WideTy))))
+ // Return the expression with the addrec on the outside.
+ return getAddRecExpr(getZeroExtendExpr(Start, Ty),
+ getZeroExtendExpr(Step, Ty),
+ AR->getLoop());
// Similar to above, only this time treat the step value as signed.
// This covers loops that count down.
SCEVHandle SMul =
getMulExpr(CastedBECount,
getTruncateOrSignExtend(Step, Start->getType()));
- // Check whether Start+Step*BECount has no unsigned overflow.
- if (getSignExtendExpr(SMul, WideTy) ==
- getMulExpr(getZeroExtendExpr(CastedBECount, WideTy),
- getSignExtendExpr(Step, WideTy))) {
- SCEVHandle Add = getAddExpr(Start, SMul);
- if (getZeroExtendExpr(Add, WideTy) ==
- getAddExpr(getZeroExtendExpr(Start, WideTy),
- getSignExtendExpr(SMul, WideTy)))
- // Return the expression with the addrec on the outside.
- return getAddRecExpr(getZeroExtendExpr(Start, Ty),
- getSignExtendExpr(Step, Ty),
- AR->getLoop());
- }
+ Add = getAddExpr(Start, SMul);
+ if (getZeroExtendExpr(Add, WideTy) ==
+ getAddExpr(getZeroExtendExpr(Start, WideTy),
+ getMulExpr(getZeroExtendExpr(CastedBECount, WideTy),
+ getSignExtendExpr(Step, WideTy))))
+ // Return the expression with the addrec on the outside.
+ return getAddRecExpr(getZeroExtendExpr(Start, Ty),
+ getSignExtendExpr(Step, Ty),
+ AR->getLoop());
}
}
}
@@ -807,37 +800,31 @@
SCEVHandle BECount = getBackedgeTakenCount(AR->getLoop());
if (!isa<SCEVCouldNotCompute>(BECount)) {
// Manually compute the final value for AR, checking for
- // overflow at each step.
+ // overflow.
SCEVHandle Start = AR->getStart();
SCEVHandle Step = AR->getStepRecurrence(*this);
// Check whether the backedge-taken count can be losslessly casted to
- // the addrec's type. The count needs to be the same whether sign
- // extended or zero extended.
+ // the addrec's type. The count is always unsigned.
SCEVHandle CastedBECount =
getTruncateOrZeroExtend(BECount, Start->getType());
if (BECount ==
- getTruncateOrZeroExtend(CastedBECount, BECount->getType()) &&
- BECount ==
- getTruncateOrSignExtend(CastedBECount, BECount->getType())) {
+ getTruncateOrZeroExtend(CastedBECount, BECount->getType())) {
const Type *WideTy =
IntegerType::get(getTypeSizeInBits(Start->getType()) * 2);
+ // Check whether Start+Step*BECount has no signed overflow.
SCEVHandle SMul =
getMulExpr(CastedBECount,
getTruncateOrSignExtend(Step, Start->getType()));
- // Check whether Start+Step*BECount has no signed overflow.
- if (getSignExtendExpr(SMul, WideTy) ==
- getMulExpr(getSignExtendExpr(CastedBECount, WideTy),
- getSignExtendExpr(Step, WideTy))) {
- SCEVHandle Add = getAddExpr(Start, SMul);
- if (getSignExtendExpr(Add, WideTy) ==
- getAddExpr(getSignExtendExpr(Start, WideTy),
- getSignExtendExpr(SMul, WideTy)))
- // Return the expression with the addrec on the outside.
- return getAddRecExpr(getSignExtendExpr(Start, Ty),
- getSignExtendExpr(Step, Ty),
- AR->getLoop());
- }
+ SCEVHandle Add = getAddExpr(Start, SMul);
+ if (getSignExtendExpr(Add, WideTy) ==
+ getAddExpr(getSignExtendExpr(Start, WideTy),
+ getMulExpr(getZeroExtendExpr(CastedBECount, WideTy),
+ getSignExtendExpr(Step, WideTy))))
+ // Return the expression with the addrec on the outside.
+ return getAddRecExpr(getSignExtendExpr(Start, Ty),
+ getSignExtendExpr(Step, Ty),
+ AR->getLoop());
}
}
}
Added: llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-0.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-0.ll?rev=70421&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-0.ll (added)
+++ llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-0.ll Wed Apr 29 17:28:28 2009
@@ -0,0 +1,31 @@
+; RUN: llvm-as < %s | opt -disable-output -scalar-evolution -analyze \
+; RUN: | grep { --> \{-128,+,1\}<bb1> Exits: 127} | count 5
+
+; Convert (sext {-128,+,1}) to {sext(-128),+,sext(1)}, since the
+; trip count is within range where this is safe.
+
+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-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @foo(double* nocapture %x) nounwind {
+bb1.thread:
+ br label %bb1
+
+bb1: ; preds = %bb1, %bb1.thread
+ %i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ] ; <i64> [#uses=3]
+ %0 = trunc i64 %i.0.reg2mem.0 to i8 ; <i8> [#uses=1]
+ %1 = trunc i64 %i.0.reg2mem.0 to i9 ; <i8> [#uses=1]
+ %2 = sext i9 %1 to i64 ; <i64> [#uses=1]
+ %3 = getelementptr double* %x, i64 %2 ; <double*> [#uses=1]
+ %4 = load double* %3, align 8 ; <double> [#uses=1]
+ %5 = mul double %4, 3.900000e+00 ; <double> [#uses=1]
+ %6 = sext i8 %0 to i64 ; <i64> [#uses=1]
+ %7 = getelementptr double* %x, i64 %6 ; <double*> [#uses=1]
+ store double %5, double* %7, align 8
+ %8 = add i64 %i.0.reg2mem.0, 1 ; <i64> [#uses=2]
+ %9 = icmp sgt i64 %8, 127 ; <i1> [#uses=1]
+ br i1 %9, label %return, label %bb1
+
+return: ; preds = %bb1
+ ret void
+}
Added: llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-1.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-1.ll?rev=70421&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-1.ll (added)
+++ llvm/trunk/test/Analysis/ScalarEvolution/sext-iv-1.ll Wed Apr 29 17:28:28 2009
@@ -0,0 +1,100 @@
+; RUN: llvm-as < %s | opt -disable-output -scalar-evolution -analyze \
+; RUN: | grep { --> (sext i. \{.\*,+,.\*\}<bb1> to i64)} | count 5
+
+; Don't convert (sext {...,+,...}) to {sext(...),+,sext(...)} in cases
+; where the trip count is not within range.
+
+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-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @foo0(double* nocapture %x) nounwind {
+bb1.thread:
+ br label %bb1
+
+bb1: ; preds = %bb1, %bb1.thread
+ %i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ] ; <i64> [#uses=3]
+ %0 = trunc i64 %i.0.reg2mem.0 to i7 ; <i8> [#uses=1]
+ %1 = trunc i64 %i.0.reg2mem.0 to i9 ; <i8> [#uses=1]
+ %2 = sext i9 %1 to i64 ; <i64> [#uses=1]
+ %3 = getelementptr double* %x, i64 %2 ; <double*> [#uses=1]
+ %4 = load double* %3, align 8 ; <double> [#uses=1]
+ %5 = mul double %4, 3.900000e+00 ; <double> [#uses=1]
+ %6 = sext i7 %0 to i64 ; <i64> [#uses=1]
+ %7 = getelementptr double* %x, i64 %6 ; <double*> [#uses=1]
+ store double %5, double* %7, align 8
+ %8 = add i64 %i.0.reg2mem.0, 1 ; <i64> [#uses=2]
+ %9 = icmp sgt i64 %8, 127 ; <i1> [#uses=1]
+ br i1 %9, label %return, label %bb1
+
+return: ; preds = %bb1
+ ret void
+}
+
+define void @foo1(double* nocapture %x) nounwind {
+bb1.thread:
+ br label %bb1
+
+bb1: ; preds = %bb1, %bb1.thread
+ %i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ] ; <i64> [#uses=3]
+ %0 = trunc i64 %i.0.reg2mem.0 to i8 ; <i8> [#uses=1]
+ %1 = trunc i64 %i.0.reg2mem.0 to i9 ; <i8> [#uses=1]
+ %2 = sext i9 %1 to i64 ; <i64> [#uses=1]
+ %3 = getelementptr double* %x, i64 %2 ; <double*> [#uses=1]
+ %4 = load double* %3, align 8 ; <double> [#uses=1]
+ %5 = mul double %4, 3.900000e+00 ; <double> [#uses=1]
+ %6 = sext i8 %0 to i64 ; <i64> [#uses=1]
+ %7 = getelementptr double* %x, i64 %6 ; <double*> [#uses=1]
+ store double %5, double* %7, align 8
+ %8 = add i64 %i.0.reg2mem.0, 1 ; <i64> [#uses=2]
+ %9 = icmp sgt i64 %8, 128 ; <i1> [#uses=1]
+ br i1 %9, label %return, label %bb1
+
+return: ; preds = %bb1
+ ret void
+}
+
+define void @foo2(double* nocapture %x) nounwind {
+bb1.thread:
+ br label %bb1
+
+bb1: ; preds = %bb1, %bb1.thread
+ %i.0.reg2mem.0 = phi i64 [ -129, %bb1.thread ], [ %8, %bb1 ] ; <i64> [#uses=3]
+ %0 = trunc i64 %i.0.reg2mem.0 to i8 ; <i8> [#uses=1]
+ %1 = trunc i64 %i.0.reg2mem.0 to i9 ; <i8> [#uses=1]
+ %2 = sext i9 %1 to i64 ; <i64> [#uses=1]
+ %3 = getelementptr double* %x, i64 %2 ; <double*> [#uses=1]
+ %4 = load double* %3, align 8 ; <double> [#uses=1]
+ %5 = mul double %4, 3.900000e+00 ; <double> [#uses=1]
+ %6 = sext i8 %0 to i64 ; <i64> [#uses=1]
+ %7 = getelementptr double* %x, i64 %6 ; <double*> [#uses=1]
+ store double %5, double* %7, align 8
+ %8 = add i64 %i.0.reg2mem.0, 1 ; <i64> [#uses=2]
+ %9 = icmp sgt i64 %8, 127 ; <i1> [#uses=1]
+ br i1 %9, label %return, label %bb1
+
+return: ; preds = %bb1
+ ret void
+}
+
+define void @foo3(double* nocapture %x) nounwind {
+bb1.thread:
+ br label %bb1
+
+bb1: ; preds = %bb1, %bb1.thread
+ %i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ] ; <i64> [#uses=3]
+ %0 = trunc i64 %i.0.reg2mem.0 to i8 ; <i8> [#uses=1]
+ %1 = trunc i64 %i.0.reg2mem.0 to i9 ; <i8> [#uses=1]
+ %2 = sext i9 %1 to i64 ; <i64> [#uses=1]
+ %3 = getelementptr double* %x, i64 %2 ; <double*> [#uses=1]
+ %4 = load double* %3, align 8 ; <double> [#uses=1]
+ %5 = mul double %4, 3.900000e+00 ; <double> [#uses=1]
+ %6 = sext i8 %0 to i64 ; <i64> [#uses=1]
+ %7 = getelementptr double* %x, i64 %6 ; <double*> [#uses=1]
+ store double %5, double* %7, align 8
+ %8 = add i64 %i.0.reg2mem.0, -1 ; <i64> [#uses=2]
+ %9 = icmp sgt i64 %8, 127 ; <i1> [#uses=1]
+ br i1 %9, label %return, label %bb1
+
+return: ; preds = %bb1
+ ret void
+}
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