llvm-6502/test/Transforms/InstCombine/load-cmp.ll
David Majnemer 024d943bca Reorders two transforms that collide with each other
One performs: (X == 13 | X == 14) -> X-13 <u 2
The other: (A == C1 || A == C2) -> (A & ~(C1 ^ C2)) == C1

The problem is that there are certain values of C1 and C2 that
trigger both transforms but the first one blocks out the second,
this generates suboptimal code.

Reordering the transforms should be better in every case and
allows us to do interesting stuff like turn:
  %shr = lshr i32 %X, 4
  %and = and i32 %shr, 15
  %add = add i32 %and, -14
  %tobool = icmp ne i32 %add, 0

into:
  %and = and i32 %X, 240
  %tobool = icmp ne i32 %and, 224


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179493 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-14 21:15:43 +00:00

125 lines
3.1 KiB
LLVM

; RUN: opt < %s -instcombine -S | FileCheck %s
@G16 = internal constant [10 x i16] [i16 35, i16 82, i16 69, i16 81, i16 85,
i16 73, i16 82, i16 69, i16 68, i16 0]
@GD = internal constant [6 x double]
[double -10.0, double 1.0, double 4.0, double 2.0, double -20.0, double -40.0]
define i1 @test1(i32 %X) {
%P = getelementptr inbounds [10 x i16]* @G16, i32 0, i32 %X
%Q = load i16* %P
%R = icmp eq i16 %Q, 0
ret i1 %R
; CHECK: @test1
; CHECK-NEXT: %R = icmp eq i32 %X, 9
; CHECK-NEXT: ret i1 %R
}
define i1 @test2(i32 %X) {
%P = getelementptr inbounds [10 x i16]* @G16, i32 0, i32 %X
%Q = load i16* %P
%R = icmp slt i16 %Q, 85
ret i1 %R
; CHECK: @test2
; CHECK-NEXT: %R = icmp ne i32 %X, 4
; CHECK-NEXT: ret i1 %R
}
define i1 @test3(i32 %X) {
%P = getelementptr inbounds [6 x double]* @GD, i32 0, i32 %X
%Q = load double* %P
%R = fcmp oeq double %Q, 1.0
ret i1 %R
; CHECK: @test3
; CHECK-NEXT: %R = icmp eq i32 %X, 1
; CHECK-NEXT: ret i1 %R
}
define i1 @test4(i32 %X) {
%P = getelementptr inbounds [10 x i16]* @G16, i32 0, i32 %X
%Q = load i16* %P
%R = icmp sle i16 %Q, 73
ret i1 %R
; CHECK: @test4
; CHECK-NEXT: lshr i32 933, %X
; CHECK-NEXT: and i32 {{.*}}, 1
; CHECK-NEXT: %R = icmp ne i32 {{.*}}, 0
; CHECK-NEXT: ret i1 %R
}
define i1 @test4_i16(i16 %X) {
%P = getelementptr inbounds [10 x i16]* @G16, i32 0, i16 %X
%Q = load i16* %P
%R = icmp sle i16 %Q, 73
ret i1 %R
; CHECK: @test4_i16
; CHECK-NEXT: lshr i16 933, %X
; CHECK-NEXT: and i16 {{.*}}, 1
; CHECK-NEXT: %R = icmp ne i16 {{.*}}, 0
; CHECK-NEXT: ret i1 %R
}
define i1 @test5(i32 %X) {
%P = getelementptr inbounds [10 x i16]* @G16, i32 0, i32 %X
%Q = load i16* %P
%R = icmp eq i16 %Q, 69
ret i1 %R
; CHECK: @test5
; CHECK-NEXT: icmp eq i32 %X, 2
; CHECK-NEXT: icmp eq i32 %X, 7
; CHECK-NEXT: %R = or i1
; CHECK-NEXT: ret i1 %R
}
define i1 @test6(i32 %X) {
%P = getelementptr inbounds [6 x double]* @GD, i32 0, i32 %X
%Q = load double* %P
%R = fcmp ogt double %Q, 0.0
ret i1 %R
; CHECK: @test6
; CHECK-NEXT: add i32 %X, -1
; CHECK-NEXT: %R = icmp ult i32 {{.*}}, 3
; CHECK-NEXT: ret i1 %R
}
define i1 @test7(i32 %X) {
%P = getelementptr inbounds [6 x double]* @GD, i32 0, i32 %X
%Q = load double* %P
%R = fcmp olt double %Q, 0.0
ret i1 %R
; CHECK: @test7
; CHECK-NEXT: add i32 %X, -1
; CHECK-NEXT: %R = icmp ugt i32 {{.*}}, 2
; CHECK-NEXT: ret i1 %R
}
define i1 @test8(i32 %X) {
%P = getelementptr inbounds [10 x i16]* @G16, i32 0, i32 %X
%Q = load i16* %P
%R = and i16 %Q, 3
%S = icmp eq i16 %R, 0
ret i1 %S
; CHECK: @test8
; CHECK-NEXT: and i32 %X, -2
; CHECK-NEXT: icmp eq i32 {{.*}}, 8
; CHECK-NEXT: ret i1
}
@GA = internal constant [4 x { i32, i32 } ] [
{ i32, i32 } { i32 1, i32 0 },
{ i32, i32 } { i32 2, i32 1 },
{ i32, i32 } { i32 3, i32 1 },
{ i32, i32 } { i32 4, i32 0 }
]
define i1 @test9(i32 %X) {
%P = getelementptr inbounds [4 x { i32, i32 } ]* @GA, i32 0, i32 %X, i32 1
%Q = load i32* %P
%R = icmp eq i32 %Q, 1
ret i1 %R
; CHECK: @test9
; CHECK-NEXT: add i32 %X, -1
; CHECK-NEXT: icmp ult i32 {{.*}}, 2
; CHECK-NEXT: ret i1
}