[all-commits] [llvm/llvm-project] c98268: [EarlyCSE] Equivalent SELECTs should hash equally
Bryan Chan via All-commits
all-commits at lists.llvm.org
Thu Sep 10 14:00:42 PDT 2020
Branch: refs/heads/master
Home: https://github.com/llvm/llvm-project
Commit: c9826829d74e637163fdb0351870b8204e62d6e6
https://github.com/llvm/llvm-project/commit/c9826829d74e637163fdb0351870b8204e62d6e6
Author: Bryan Chan <bryan.chan at huawei.com>
Date: 2020-09-10 (Thu, 10 Sep 2020)
Changed paths:
M llvm/lib/Transforms/Scalar/EarlyCSE.cpp
M llvm/test/Transforms/EarlyCSE/commute.ll
Log Message:
-----------
[EarlyCSE] Equivalent SELECTs should hash equally
DenseMap<SimpleValue> assumes that, if its isEqual method returns true
for two elements, then its getHashValue method must return the same value
for them. This invariant is broken when one SELECT node is a min/max
operation, and the other can be transformed into an equivalent min/max by
inverting its predicate and swapping its operands. This patch fixes an
assertion failure that would occur intermittently while compiling the
following IR:
define i32 @t(i32 %i) {
%cmp = icmp sle i32 0, %i
%twin1 = select i1 %cmp, i32 %i, i32 0
%cmpinv = icmp sgt i32 0, %i
%twin2 = select i1 %cmpinv, i32 0, i32 %i
%sink = add i32 %twin1, %twin2
ret i32 %sink
}
Differential Revision: https://reviews.llvm.org/D86843
More information about the All-commits
mailing list