llvm-6502/test/Transforms/InstCombine/2008-11-08-FCmp.ll
Bob Wilson f12c95a8af Fix a serious typo in InstCombine's optimization of comparisons.
An unsigned value converted to floating-point will always be greater than
a negative constant.  Unfortunately InstCombine reversed the check so that
unsigned values were being optimized to always be greater than all positive
floating-point constants.  <rdar://problem/12029145>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161452 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-07 22:35:16 +00:00

57 lines
1.3 KiB
LLVM

; RUN: opt < %s -instcombine -S | FileCheck %s
; PR3021
; When inst combining an FCMP with the LHS coming from a uitofp instruction, we
; can't lower it to signed ICMP instructions.
define i1 @test1(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp ole double %1, 0.000000e+00
; CHECK: icmp eq i32 %val, 0
ret i1 %2
}
define i1 @test2(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp olt double %1, 0.000000e+00
ret i1 %2
; CHECK: ret i1 false
}
define i1 @test3(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp oge double %1, 0.000000e+00
ret i1 %2
; CHECK: ret i1 true
}
define i1 @test4(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp ogt double %1, 0.000000e+00
; CHECK: icmp ne i32 %val, 0
ret i1 %2
}
define i1 @test5(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp ogt double %1, -4.400000e+00
ret i1 %2
; CHECK: ret i1 true
}
define i1 @test6(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp olt double %1, -4.400000e+00
ret i1 %2
; CHECK: ret i1 false
}
; Check that optimizing unsigned >= comparisons correctly distinguishes
; positive and negative constants. <rdar://problem/12029145>
define i1 @test7(i32 %val) {
%1 = uitofp i32 %val to double
%2 = fcmp oge double %1, 3.200000e+00
ret i1 %2
; CHECK: icmp ugt i32 %val, 3
}