llvm/test/CodeGen/ARM/fpcmp.ll
James Molloy 9b264f7915 [ARM] Use VCMP, not VCMPE, for floating point equality comparisons
When generating a floating point comparison we currently unconditionally
generate VCMPE. This has the sideeffect of setting the cumulative Invalid
bit in FPSCR if any of the operands are QNaN.

It is expected that use of a relational predicate on a QNaN value should
raise Invalid. Quoting from the C standard:

  The relational and equality operators support the usual mathematical
  relationships between numeric values. For any ordered pair of numeric
  values exactly one of relationships the less, greater, equal and is true.
  Relational operators may raise the floating-point exception when argument
  values are NaNs.

The standard doesn't explicitly state the expectation for equality operators,
but the implication and obvious expectation is that equality operators
should not raise Invalid on a QNaN input, as those predicates are wholly
defined on unordered inputs (to return not equal).

Therefore, add a new operand to ARMISD::FPCMP and FPCMPZ indicating if
QNaN should raise Invalid, and pipe that through to TableGen.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294945 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-13 12:32:47 +00:00

72 lines
1.8 KiB
LLVM

; RUN: llc -mtriple=arm-eabi -mattr=+vfp2 %s -o - | FileCheck %s
define i32 @f1(float %a) {
;CHECK-LABEL: f1:
;CHECK: vcmpe.f32
;CHECK: movmi
entry:
%tmp = fcmp olt float %a, 1.000000e+00 ; <i1> [#uses=1]
%tmp1 = zext i1 %tmp to i32 ; <i32> [#uses=1]
ret i32 %tmp1
}
define i32 @f2(float %a) {
;CHECK-LABEL: f2:
;CHECK: vcmp.f32
;CHECK: moveq
entry:
%tmp = fcmp oeq float %a, 1.000000e+00 ; <i1> [#uses=1]
%tmp2 = zext i1 %tmp to i32 ; <i32> [#uses=1]
ret i32 %tmp2
}
define i32 @f3(float %a) {
;CHECK-LABEL: f3:
;CHECK: vcmpe.f32
;CHECK: movgt
entry:
%tmp = fcmp ogt float %a, 1.000000e+00 ; <i1> [#uses=1]
%tmp3 = zext i1 %tmp to i32 ; <i32> [#uses=1]
ret i32 %tmp3
}
define i32 @f4(float %a) {
;CHECK-LABEL: f4:
;CHECK: vcmpe.f32
;CHECK: movge
entry:
%tmp = fcmp oge float %a, 1.000000e+00 ; <i1> [#uses=1]
%tmp4 = zext i1 %tmp to i32 ; <i32> [#uses=1]
ret i32 %tmp4
}
define i32 @f5(float %a) {
;CHECK-LABEL: f5:
;CHECK: vcmpe.f32
;CHECK: movls
entry:
%tmp = fcmp ole float %a, 1.000000e+00 ; <i1> [#uses=1]
%tmp5 = zext i1 %tmp to i32 ; <i32> [#uses=1]
ret i32 %tmp5
}
define i32 @f6(float %a) {
;CHECK-LABEL: f6:
;CHECK: vcmp.f32
;CHECK: movne
entry:
%tmp = fcmp une float %a, 1.000000e+00 ; <i1> [#uses=1]
%tmp6 = zext i1 %tmp to i32 ; <i32> [#uses=1]
ret i32 %tmp6
}
define i32 @g1(double %a) {
;CHECK-LABEL: g1:
;CHECK: vcmpe.f64
;CHECK: movmi
entry:
%tmp = fcmp olt double %a, 1.000000e+00 ; <i1> [#uses=1]
%tmp7 = zext i1 %tmp to i32 ; <i32> [#uses=1]
ret i32 %tmp7
}