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llvm-project/llvm/test/Analysis/ValueTracking/known-bits-from-range-md.ll

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InstCombine: Restrict computeKnownBits() on all Values to OptLevel > 2 As part of r251146 InstCombine was extended to call computeKnownBits on every value in the function to determine whether it happens to be constant. This increases typical compiletime by 1-3% (5% in irgen+opt time) in my measurements. On the other hand this case did not trigger once in the whole llvm-testsuite. This patch introduces the notion of ExpensiveCombines which are only enabled for OptLevel > 2. I removed the check in InstructionSimplify as that is called from various places where the OptLevel is not known but given the rarity of the situation I think a check in InstCombine is enough. Differential Revision: http://reviews.llvm.org/D16835 llvm-svn: 263047
2016-03-10 02:47:11 +08:00
; RUN: opt -S -instsimplify -instcombine < %s | FileCheck %s
[ValueTracking] Use !range metadata more aggressively in KnownBits Summary: Teach `computeKnownBitsFromRangeMetadata` to use `!range` metadata more aggressively. Reviewers: majnemer, nlewycky, jingyue Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D14100 llvm-svn: 251487
2015-10-28 11:20:15 +08:00
define i1 @test0(i8* %ptr) {
; CHECK-LABEL: @test0(
entry:
%val = load i8, i8* %ptr, !range !{i8 -50, i8 0}
%and = and i8 %val, 128
%is.eq = icmp eq i8 %and, 128
ret i1 %is.eq
; CHECK: ret i1 true
}
define i1 @test1(i8* %ptr) {
; CHECK-LABEL: @test1(
entry:
%val = load i8, i8* %ptr, !range !{i8 64, i8 128}
%and = and i8 %val, 64
%is.eq = icmp eq i8 %and, 64
ret i1 %is.eq
; CHECK: ret i1 true
}
define i1 @test2(i8* %ptr) {
; CHECK-LABEL: @test2(
entry:
InstCombine: Restrict computeKnownBits() on all Values to OptLevel > 2 As part of r251146 InstCombine was extended to call computeKnownBits on every value in the function to determine whether it happens to be constant. This increases typical compiletime by 1-3% (5% in irgen+opt time) in my measurements. On the other hand this case did not trigger once in the whole llvm-testsuite. This patch introduces the notion of ExpensiveCombines which are only enabled for OptLevel > 2. I removed the check in InstructionSimplify as that is called from various places where the OptLevel is not known but given the rarity of the situation I think a check in InstCombine is enough. Differential Revision: http://reviews.llvm.org/D16835 llvm-svn: 263047
2016-03-10 02:47:11 +08:00
; CHECK: %val = load i8
; CHECK: %and = and i8 %val
; CHECK: %is.eq = icmp ne i8 %and, 0
; CHECK: ret i1 %is.eq
[ValueTracking] Use !range metadata more aggressively in KnownBits Summary: Teach `computeKnownBitsFromRangeMetadata` to use `!range` metadata more aggressively. Reviewers: majnemer, nlewycky, jingyue Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D14100 llvm-svn: 251487
2015-10-28 11:20:15 +08:00
%val = load i8, i8* %ptr, !range !{i8 64, i8 129}
%and = and i8 %val, 64
%is.eq = icmp eq i8 %and, 64
ret i1 %is.eq
}