[llvm] r268636 - [ValueTracking] Improve isImpliedCondition for matching LHS and Imm RHSs.
Chad Rosier via llvm-commits
llvm-commits at lists.llvm.org
Thu May 5 08:39:19 PDT 2016
Author: mcrosier
Date: Thu May 5 10:39:18 2016
New Revision: 268636
URL: http://llvm.org/viewvc/llvm-project?rev=268636&view=rev
Log:
[ValueTracking] Improve isImpliedCondition for matching LHS and Imm RHSs.
Added:
llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-imm.ll
Modified:
llvm/trunk/lib/Analysis/ValueTracking.cpp
llvm/trunk/test/CodeGen/AArch64/addsub.ll
llvm/trunk/test/CodeGen/AArch64/combine-comparisons-by-cse.ll
llvm/trunk/test/Transforms/InstCombine/select-implied.ll
Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=268636&r1=268635&r2=268636&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Thu May 5 10:39:18 2016
@@ -3948,6 +3948,27 @@ static Optional<bool> isImpliedCondMatch
return None;
}
+/// Return true if "icmp1 APred ALHS C1" implies "icmp2 BPred BLHS C2" is
+/// true. Return false if "icmp1 APred ALHS C1" implies "icmp2 BPred BLHS
+/// C2" is false. Otherwise, return None if we can't infer anything.
+static Optional<bool>
+isImpliedCondMatchingImmOperands(CmpInst::Predicate APred, Value *ALHS,
+ ConstantInt *C1, CmpInst::Predicate BPred,
+ Value *BLHS, ConstantInt *C2) {
+ assert(ALHS == BLHS && "LHS operands must match.");
+ ConstantRange DomCR =
+ ConstantRange::makeExactICmpRegion(APred, C1->getValue());
+ ConstantRange CR =
+ ConstantRange::makeAllowedICmpRegion(BPred, C2->getValue());
+ ConstantRange Intersection = DomCR.intersectWith(CR);
+ ConstantRange Difference = DomCR.difference(CR);
+ if (Intersection.isEmptySet())
+ return false;
+ if (Difference.isEmptySet())
+ return true;
+ return None;
+}
+
Optional<bool> llvm::isImpliedCondition(Value *LHS, Value *RHS,
const DataLayout &DL, bool InvertAPred,
unsigned Depth, AssumptionCache *AC,
@@ -3985,6 +4006,14 @@ Optional<bool> llvm::isImpliedCondition(
if (Implication)
return Implication;
+ if (ALHS == BLHS && isa<ConstantInt>(ARHS) && isa<ConstantInt>(BRHS)) {
+ Implication =
+ isImpliedCondMatchingImmOperands(APred, ALHS, cast<ConstantInt>(ARHS),
+ BPred, BLHS, cast<ConstantInt>(BRHS));
+ if (Implication)
+ return Implication;
+ }
+
if (APred == BPred)
return isImpliedCondOperands(APred, ALHS, ARHS, BLHS, BRHS, DL, Depth, AC,
CxtI, DT);
Modified: llvm/trunk/test/CodeGen/AArch64/addsub.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/addsub.ll?rev=268636&r1=268635&r2=268636&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/addsub.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/addsub.ll Thu May 5 10:39:18 2016
@@ -5,6 +5,7 @@
; loads and stores.
@var_i32 = global i32 42
+ at var2_i32 = global i32 43
@var_i64 = global i64 0
; Add pure 12-bit immediates:
@@ -106,6 +107,7 @@ define void @sub_med() {
define void @testing() {
; CHECK-LABEL: testing:
%val = load i32, i32* @var_i32
+ %val2 = load i32, i32* @var2_i32
; CHECK: cmp {{w[0-9]+}}, #4095
; CHECK: b.ne [[RET:.?LBB[0-9]+_[0-9]+]]
@@ -117,7 +119,7 @@ test2:
; CHECK: b.lo [[RET]]
%newval2 = add i32 %val, 1
store i32 %newval2, i32* @var_i32
- %cmp_pos_big = icmp ult i32 %val, 14610432
+ %cmp_pos_big = icmp ult i32 %val2, 14610432
br i1 %cmp_pos_big, label %ret, label %test3
test3:
@@ -133,7 +135,7 @@ test4:
; CHECK: b.gt [[RET]]
%newval4 = add i32 %val, 3
store i32 %newval4, i32* @var_i32
- %cmp_pos_sgt = icmp sgt i32 %val, 321
+ %cmp_pos_sgt = icmp sgt i32 %val2, 321
br i1 %cmp_pos_sgt, label %ret, label %test5
test5:
@@ -141,7 +143,7 @@ test5:
; CHECK: b.gt [[RET]]
%newval5 = add i32 %val, 4
store i32 %newval5, i32* @var_i32
- %cmp_neg_uge = icmp sgt i32 %val, -444
+ %cmp_neg_uge = icmp sgt i32 %val2, -444
br i1 %cmp_neg_uge, label %ret, label %test6
test6:
Modified: llvm/trunk/test/CodeGen/AArch64/combine-comparisons-by-cse.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/combine-comparisons-by-cse.ll?rev=268636&r1=268635&r2=268636&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/combine-comparisons-by-cse.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/combine-comparisons-by-cse.ll Thu May 5 10:39:18 2016
@@ -405,11 +405,11 @@ return:
define void @cmp_shifted(i32 %in, i32 %lhs, i32 %rhs) {
; CHECK-LABEL: cmp_shifted:
-; CHECK: cmp w0, #1
-; [...]
; CHECK: cmp w0, #2, lsl #12
+; [...]
+; CHECK: cmp w0, #1
- %tst_low = icmp sgt i32 %in, 0
+ %tst_low = icmp sgt i32 %in, 8191
br i1 %tst_low, label %true, label %false
true:
@@ -417,7 +417,7 @@ true:
ret void
false:
- %tst = icmp sgt i32 %in, 8191
+ %tst = icmp sgt i32 %in, 0
br i1 %tst, label %truer, label %falser
truer:
Modified: llvm/trunk/test/Transforms/InstCombine/select-implied.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/select-implied.ll?rev=268636&r1=268635&r2=268636&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/select-implied.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/select-implied.ll Thu May 5 10:39:18 2016
@@ -40,7 +40,7 @@ end:
; CHECK-LABEL: @test3
; CHECK-NOT: select
; CHECK: call void @foo(i32 30)
-define void @test3(i32 %a, i32 %b) {
+define void @test3(i32 %a) {
%cmp1 = icmp ugt i32 %a, 10
br i1 %cmp1, label %taken, label %end
@@ -101,5 +101,23 @@ ret:
ret void
}
+; A >u 10 implies A >u 9 is true.
+; CHECK-LABEL: @test5
+; CHECK-NOT: select
+; CHECK: call void @foo(i32 30)
+define void @test5(i32 %a) {
+ %cmp1 = icmp ugt i32 %a, 10
+ br i1 %cmp1, label %taken, label %end
+
+taken:
+ %cmp2 = icmp ugt i32 %a, 9
+ %c = select i1 %cmp2, i32 30, i32 0
+ call void @foo(i32 %c)
+ br label %end
+
+end:
+ ret void
+}
+
declare void @foo(i32)
declare i32 @bar(i32)
Added: llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-imm.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-imm.ll?rev=268636&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-imm.ll (added)
+++ llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-imm.ll Thu May 5 10:39:18 2016
@@ -0,0 +1,123 @@
+; RUN: opt %s -S -simplifycfg | FileCheck %s
+
+; cmp1 implies cmp2 is false
+; CHECK-LABEL: @test1
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test1(i32 %a) {
+ %cmp1 = icmp eq i32 %a, 0
+ br i1 %cmp1, label %taken, label %untaken
+
+taken:
+ %cmp2 = icmp eq i32 %a, 1
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; cmp1 implies cmp2 is false
+; CHECK-LABEL: @test2
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test2(i32 %a) {
+ %cmp1 = icmp ugt i32 %a, 5
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ugt i32 %a, 6
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; cmp1 implies cmp2 is false
+; CHECK-LABEL: @test3
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test3(i32 %a) {
+ %cmp1 = icmp ugt i32 %a, 1
+ br i1 %cmp1, label %taken, label %untaken
+
+taken:
+ %cmp2 = icmp eq i32 %a, 0
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; cmp1 implies cmp2 is true
+; CHECK-LABEL: @test4
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test4(i32 %a) {
+ %cmp1 = icmp sgt i32 %a, 1
+ br i1 %cmp1, label %taken, label %untaken
+
+taken:
+ %cmp2 = icmp ugt i32 %a, 0
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; cmp1 implies cmp2 is true
+; CHECK-LABEL: @test5
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test5(i32 %a) {
+ %cmp1 = icmp sgt i32 %a, 5
+ br i1 %cmp1, label %taken, label %untaken
+
+taken:
+ %cmp2 = icmp sgt i32 %a, -1
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+declare void @is(i1)
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