[llvm] r371306 - [LVI] Look through extractvalue of insertvalue
Nikita Popov via llvm-commits
llvm-commits at lists.llvm.org
Sat Sep 7 05:03:59 PDT 2019
Author: nikic
Date: Sat Sep 7 05:03:59 2019
New Revision: 371306
URL: http://llvm.org/viewvc/llvm-project?rev=371306&view=rev
Log:
[LVI] Look through extractvalue of insertvalue
This addresses the issue mentioned on D19867. When we simplify
with.overflow instructions in CVP, we leave behind extractvalue
of insertvalue sequences that LVI no longer understands. This
means that we can not simplify any instructions based on the
with.overflow anymore (until some over pass like InstCombine
cleans them up).
This patch extends LVI extractvalue handling by calling
SimplifyExtractValueInst (which doesn't do anything more than
constant folding + looking through insertvalue) and using the block
value of the simplification.
A possible alternative would be to do something similar to
SimplifyIndVars, where we instead directly try to replace
extractvalue users of the with.overflow. This would need some
additional structural changes to CVP, as it's currently not legal
to remove anything but the current instruction -- we'd have to
introduce a worklist with instructions scheduled for deletion or similar.
Differential Revision: https://reviews.llvm.org/D67035
Modified:
llvm/trunk/lib/Analysis/LazyValueInfo.cpp
llvm/trunk/test/Transforms/CorrelatedValuePropagation/overflows.ll
Modified: llvm/trunk/lib/Analysis/LazyValueInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LazyValueInfo.cpp?rev=371306&r1=371305&r2=371306&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/LazyValueInfo.cpp (original)
+++ llvm/trunk/lib/Analysis/LazyValueInfo.cpp Sat Sep 7 05:03:59 2019
@@ -1141,6 +1141,21 @@ bool LazyValueInfoImpl::solveBlockValueE
if (EVI->getNumIndices() == 1 && *EVI->idx_begin() == 0)
return solveBlockValueOverflowIntrinsic(BBLV, WO, BB);
+ // Handle extractvalue of insertvalue to allow further simplification
+ // based on replaced with.overflow intrinsics.
+ if (Value *V = SimplifyExtractValueInst(
+ EVI->getAggregateOperand(), EVI->getIndices(),
+ EVI->getModule()->getDataLayout())) {
+ if (!hasBlockValue(V, BB)) {
+ if (pushBlockValue({ BB, V }))
+ return false;
+ BBLV = ValueLatticeElement::getOverdefined();
+ return true;
+ }
+ BBLV = getBlockValue(V, BB);
+ return true;
+ }
+
LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()
<< "' - overdefined (unknown extractvalue).\n");
BBLV = ValueLatticeElement::getOverdefined();
Modified: llvm/trunk/test/Transforms/CorrelatedValuePropagation/overflows.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CorrelatedValuePropagation/overflows.ll?rev=371306&r1=371305&r2=371306&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/CorrelatedValuePropagation/overflows.ll (original)
+++ llvm/trunk/test/Transforms/CorrelatedValuePropagation/overflows.ll Sat Sep 7 05:03:59 2019
@@ -850,11 +850,9 @@ define i1 @sadd_and_cmp(i32 %x, i32 %y)
; CHECK-NEXT: [[ADD:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
; CHECK: cont3:
-; CHECK-NEXT: [[CMP3:%.*]] = icmp slt i32 [[ADD]], 19
; CHECK-NEXT: br label [[OUT]]
; CHECK: out:
-; CHECK-NEXT: [[RET:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ true, [[CONT1]] ], [ [[CMP3]], [[CONT3]] ]
-; CHECK-NEXT: ret i1 [[RET]]
+; CHECK-NEXT: ret i1 true
;
entry:
%x.offset = add i32 %x, 9
@@ -897,11 +895,9 @@ define i1 @uadd_and_cmp(i32 %x, i32 %y)
; CHECK-NEXT: [[ADD:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
; CHECK: cont3:
-; CHECK-NEXT: [[CMP3:%.*]] = icmp ult i32 [[ADD]], 19
; CHECK-NEXT: br label [[OUT]]
; CHECK: out:
-; CHECK-NEXT: [[RET:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ true, [[CONT1]] ], [ [[CMP3]], [[CONT3]] ]
-; CHECK-NEXT: ret i1 [[RET]]
+; CHECK-NEXT: ret i1 true
;
entry:
%cmp1 = icmp ult i32 %x, 10
@@ -940,11 +936,9 @@ define i1 @ssub_and_cmp(i32 %x, i32 %y)
; CHECK-NEXT: [[SUB:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
; CHECK: cont3:
-; CHECK-NEXT: [[CMP3:%.*]] = icmp ult i32 [[SUB]], 19
; CHECK-NEXT: br label [[OUT]]
; CHECK: out:
-; CHECK-NEXT: [[RET:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ true, [[CONT1]] ], [ [[CMP3]], [[CONT3]] ]
-; CHECK-NEXT: ret i1 [[RET]]
+; CHECK-NEXT: ret i1 true
;
entry:
%cmp1 = icmp ult i32 %x, 10
@@ -985,11 +979,9 @@ define i1 @usub_and_cmp(i32 %x, i32 %y)
; CHECK-NEXT: [[SUB:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
; CHECK: cont3:
-; CHECK-NEXT: [[CMP3:%.*]] = icmp ult i32 [[SUB]], 19
; CHECK-NEXT: br label [[OUT]]
; CHECK: out:
-; CHECK-NEXT: [[RET:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ true, [[CONT1]] ], [ [[CMP3]], [[CONT3]] ]
-; CHECK-NEXT: ret i1 [[RET]]
+; CHECK-NEXT: ret i1 true
;
entry:
%cmp1 = icmp ult i32 %x, 10
@@ -1031,13 +1023,10 @@ define i1 @smul_and_cmp(i32 %x, i32 %y)
; CHECK-NEXT: [[MUL:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
; CHECK: cont3:
-; CHECK-NEXT: [[CMP3:%.*]] = icmp sle i32 [[MUL]], 81
-; CHECK-NEXT: [[CMP4:%.*]] = icmp sge i32 [[MUL]], -81
-; CHECK-NEXT: [[CMP5:%.*]] = and i1 [[CMP3]], [[CMP4]]
+; CHECK-NEXT: [[CMP5:%.*]] = and i1 true, true
; CHECK-NEXT: br label [[OUT]]
; CHECK: out:
-; CHECK-NEXT: [[RET:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ true, [[CONT1]] ], [ [[CMP5]], [[CONT3]] ]
-; CHECK-NEXT: ret i1 [[RET]]
+; CHECK-NEXT: ret i1 true
;
entry:
%x.offset = add i32 %x, 9
@@ -1080,11 +1069,9 @@ define i1 @umul_and_cmp(i32 %x, i32 %y)
; CHECK-NEXT: [[MUL:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
; CHECK: cont3:
-; CHECK-NEXT: [[CMP3:%.*]] = icmp ule i32 [[MUL]], 9801
; CHECK-NEXT: br label [[OUT]]
; CHECK: out:
-; CHECK-NEXT: [[RET:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ true, [[CONT1]] ], [ [[CMP3]], [[CONT3]] ]
-; CHECK-NEXT: ret i1 [[RET]]
+; CHECK-NEXT: ret i1 true
;
entry:
%cmp1 = icmp ult i32 %x, 100
More information about the llvm-commits
mailing list