[llvm-commits] [llvm] r108863 - in /llvm/trunk: lib/Analysis/ScalarEvolutionNormalization.cpp test/CodeGen/X86/lsr-normalization.ll
Dan Gohman
gohman at apple.com
Tue Jul 20 10:06:20 PDT 2010
Author: djg
Date: Tue Jul 20 12:06:20 2010
New Revision: 108863
URL: http://llvm.org/viewvc/llvm-project?rev=108863&view=rev
Log:
Fix SCEV denormalization of expressions where the exit value from
one loop is involved in the increment of an addrec for another
loop. This fixes rdar://8168938.
Added:
llvm/trunk/test/CodeGen/X86/lsr-normalization.ll
Modified:
llvm/trunk/lib/Analysis/ScalarEvolutionNormalization.cpp
Modified: llvm/trunk/lib/Analysis/ScalarEvolutionNormalization.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionNormalization.cpp?rev=108863&r1=108862&r2=108863&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionNormalization.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionNormalization.cpp Tue Jul 20 12:06:20 2010
@@ -45,7 +45,7 @@
// their uses occur in the predecessor block, not the block the PHI lives in)
// should still use the post-inc value. Check for this case now.
PHINode *PN = dyn_cast<PHINode>(User);
- if (!PN) return false; // not a phi, not dominated by latch block.
+ if (!PN || !Operand) return false; // not a phi, not dominated by latch block.
// Look at all of the uses of Operand by the PHI node. If any use corresponds
// to a block that is not dominated by the latch block, give up and use the
@@ -84,6 +84,59 @@
return S;
}
+ if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) {
+ // An addrec. This is the interesting part.
+ SmallVector<const SCEV *, 8> Operands;
+ const Loop *L = AR->getLoop();
+ // The addrec conceptually uses its operands at loop entry.
+ Instruction *LUser = L->getHeader()->begin();
+ // Transform each operand.
+ for (SCEVNAryExpr::op_iterator I = AR->op_begin(), E = AR->op_end();
+ I != E; ++I) {
+ const SCEV *O = *I;
+ const SCEV *N = TransformForPostIncUse(Kind, O, LUser, 0, Loops, SE, DT);
+ Operands.push_back(N);
+ }
+ const SCEV *Result = SE.getAddRecExpr(Operands, L);
+ switch (Kind) {
+ default: llvm_unreachable("Unexpected transform name!");
+ case NormalizeAutodetect:
+ if (IVUseShouldUsePostIncValue(User, OperandValToReplace, L, &DT)) {
+ const SCEV *TransformedStep =
+ TransformForPostIncUse(Kind, AR->getStepRecurrence(SE),
+ User, OperandValToReplace, Loops, SE, DT);
+ Result = SE.getMinusSCEV(Result, TransformedStep);
+ Loops.insert(L);
+ }
+#ifdef XDEBUG
+ assert(S == TransformForPostIncUse(Denormalize, Result,
+ User, OperandValToReplace,
+ Loops, SE, DT) &&
+ "SCEV normalization is not invertible!");
+#endif
+ break;
+ case Normalize:
+ if (Loops.count(L)) {
+ const SCEV *TransformedStep =
+ TransformForPostIncUse(Kind, AR->getStepRecurrence(SE),
+ User, OperandValToReplace, Loops, SE, DT);
+ Result = SE.getMinusSCEV(Result, TransformedStep);
+ }
+#ifdef XDEBUG
+ assert(S == TransformForPostIncUse(Denormalize, Result,
+ User, OperandValToReplace,
+ Loops, SE, DT) &&
+ "SCEV normalization is not invertible!");
+#endif
+ break;
+ case Denormalize:
+ if (Loops.count(L))
+ Result = cast<SCEVAddRecExpr>(Result)->getPostIncExpr(SE);
+ break;
+ }
+ return Result;
+ }
+
if (const SCEVNAryExpr *X = dyn_cast<SCEVNAryExpr>(S)) {
SmallVector<const SCEV *, 8> Operands;
bool Changed = false;
@@ -96,37 +149,7 @@
Changed |= N != O;
Operands.push_back(N);
}
- if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) {
- // An addrec. This is the interesting part.
- const Loop *L = AR->getLoop();
- const SCEV *Result = SE.getAddRecExpr(Operands, L);
- switch (Kind) {
- default: llvm_unreachable("Unexpected transform name!");
- case NormalizeAutodetect:
- if (Instruction *OI = dyn_cast<Instruction>(OperandValToReplace))
- if (IVUseShouldUsePostIncValue(User, OI, L, &DT)) {
- const SCEV *TransformedStep =
- TransformForPostIncUse(Kind, AR->getStepRecurrence(SE),
- User, OperandValToReplace, Loops, SE, DT);
- Result = SE.getMinusSCEV(Result, TransformedStep);
- Loops.insert(L);
- }
- break;
- case Normalize:
- if (Loops.count(L)) {
- const SCEV *TransformedStep =
- TransformForPostIncUse(Kind, AR->getStepRecurrence(SE),
- User, OperandValToReplace, Loops, SE, DT);
- Result = SE.getMinusSCEV(Result, TransformedStep);
- }
- break;
- case Denormalize:
- if (Loops.count(L))
- Result = SE.getAddExpr(Result, AR->getStepRecurrence(SE));
- break;
- }
- return Result;
- }
+ // If any operand actually changed, return a transformed result.
if (Changed)
switch (S->getSCEVType()) {
case scAddExpr: return SE.getAddExpr(Operands);
Added: llvm/trunk/test/CodeGen/X86/lsr-normalization.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/lsr-normalization.ll?rev=108863&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/lsr-normalization.ll (added)
+++ llvm/trunk/test/CodeGen/X86/lsr-normalization.ll Tue Jul 20 12:06:20 2010
@@ -0,0 +1,99 @@
+; RUN: llc < %s -march=x86-64 | grep div | count 1
+; rdar://8168938
+
+; This testcase involves SCEV normalization with the exit value from
+; one loop involved with the increment value for an addrec on another
+; loop. The expression should be properly normalized and simplified,
+; and require only a single division.
+
+%0 = type { %0*, %0* }
+
+ at 0 = private constant [13 x i8] c"Result: %lu\0A\00" ; <[13 x i8]*> [#uses=1]
+ at 1 = internal constant [5 x i8] c"Huh?\00" ; <[5 x i8]*> [#uses=1]
+
+define i32 @main(i32 %arg, i8** nocapture %arg1) nounwind {
+bb:
+ %tmp = alloca %0, align 8 ; <%0*> [#uses=11]
+ %tmp2 = bitcast %0* %tmp to i8* ; <i8*> [#uses=1]
+ call void @llvm.memset.p0i8.i64(i8* %tmp2, i8 0, i64 16, i32 8, i1 false) nounwind
+ %tmp3 = getelementptr inbounds %0* %tmp, i64 0, i32 0 ; <%0**> [#uses=3]
+ store %0* %tmp, %0** %tmp3
+ %tmp4 = getelementptr inbounds %0* %tmp, i64 0, i32 1 ; <%0**> [#uses=1]
+ store %0* %tmp, %0** %tmp4
+ %tmp5 = call noalias i8* @_Znwm(i64 24) nounwind ; <i8*> [#uses=2]
+ %tmp6 = getelementptr inbounds i8* %tmp5, i64 16 ; <i8*> [#uses=2]
+ %tmp7 = icmp eq i8* %tmp6, null ; <i1> [#uses=1]
+ br i1 %tmp7, label %bb10, label %bb8
+
+bb8: ; preds = %bb
+ %tmp9 = bitcast i8* %tmp6 to i32* ; <i32*> [#uses=1]
+ store i32 1, i32* %tmp9
+ br label %bb10
+
+bb10: ; preds = %bb8, %bb
+ %tmp11 = bitcast i8* %tmp5 to %0* ; <%0*> [#uses=1]
+ call void @_ZNSt15_List_node_base4hookEPS_(%0* %tmp11, %0* %tmp) nounwind
+ %tmp12 = load %0** %tmp3 ; <%0*> [#uses=3]
+ %tmp13 = icmp eq %0* %tmp12, %tmp ; <i1> [#uses=1]
+ br i1 %tmp13, label %bb14, label %bb16
+
+bb14: ; preds = %bb10
+ %tmp15 = call i32 @puts(i8* getelementptr inbounds ([5 x i8]* @1, i64 0, i64 0))
+ br label %bb35
+
+bb16: ; preds = %bb16, %bb10
+ %tmp17 = phi i64 [ %tmp22, %bb16 ], [ 0, %bb10 ] ; <i64> [#uses=1]
+ %tmp18 = phi %0* [ %tmp20, %bb16 ], [ %tmp12, %bb10 ] ; <%0*> [#uses=1]
+ %tmp19 = getelementptr inbounds %0* %tmp18, i64 0, i32 0 ; <%0**> [#uses=1]
+ %tmp20 = load %0** %tmp19 ; <%0*> [#uses=2]
+ %tmp21 = icmp eq %0* %tmp20, %tmp ; <i1> [#uses=1]
+ %tmp22 = add i64 %tmp17, 1 ; <i64> [#uses=2]
+ br i1 %tmp21, label %bb23, label %bb16
+
+bb23: ; preds = %bb16
+ %tmp24 = udiv i64 100, %tmp22 ; <i64> [#uses=1]
+ br label %bb25
+
+bb25: ; preds = %bb25, %bb23
+ %tmp26 = phi i64 [ %tmp31, %bb25 ], [ 0, %bb23 ] ; <i64> [#uses=1]
+ %tmp27 = phi %0* [ %tmp29, %bb25 ], [ %tmp12, %bb23 ] ; <%0*> [#uses=1]
+ %tmp28 = getelementptr inbounds %0* %tmp27, i64 0, i32 0 ; <%0**> [#uses=1]
+ %tmp29 = load %0** %tmp28 ; <%0*> [#uses=2]
+ %tmp30 = icmp eq %0* %tmp29, %tmp ; <i1> [#uses=1]
+ %tmp31 = add i64 %tmp26, 1 ; <i64> [#uses=2]
+ br i1 %tmp30, label %bb32, label %bb25
+
+bb32: ; preds = %bb25
+ %tmp33 = mul i64 %tmp31, %tmp24 ; <i64> [#uses=1]
+ %tmp34 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([13 x i8]* @0, i64 0, i64 0), i64 %tmp33) nounwind
+ br label %bb35
+
+bb35: ; preds = %bb32, %bb14
+ %tmp36 = load %0** %tmp3 ; <%0*> [#uses=2]
+ %tmp37 = icmp eq %0* %tmp36, %tmp ; <i1> [#uses=1]
+ br i1 %tmp37, label %bb44, label %bb38
+
+bb38: ; preds = %bb38, %bb35
+ %tmp39 = phi %0* [ %tmp41, %bb38 ], [ %tmp36, %bb35 ] ; <%0*> [#uses=2]
+ %tmp40 = getelementptr inbounds %0* %tmp39, i64 0, i32 0 ; <%0**> [#uses=1]
+ %tmp41 = load %0** %tmp40 ; <%0*> [#uses=2]
+ %tmp42 = bitcast %0* %tmp39 to i8* ; <i8*> [#uses=1]
+ call void @_ZdlPv(i8* %tmp42) nounwind
+ %tmp43 = icmp eq %0* %tmp41, %tmp ; <i1> [#uses=1]
+ br i1 %tmp43, label %bb44, label %bb38
+
+bb44: ; preds = %bb38, %bb35
+ ret i32 0
+}
+
+declare i32 @printf(i8* nocapture, ...) nounwind
+
+declare void @_ZNSt15_List_node_base4hookEPS_(%0*, %0*)
+
+declare noalias i8* @_Znwm(i64)
+
+declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
+
+declare void @_ZdlPv(i8*) nounwind
+
+declare i32 @puts(i8* nocapture) nounwind
More information about the llvm-commits
mailing list