llvm-6502/test/CodeGen/PowerPC/fma.ll
Lang Hames d693cafcfb Add DAG-combines for aggressive FMA formation.
This patch adds DAG combines to form FMAs from pairs of FADD + FMUL or
FSUB + FMUL. The combines are performed when:
(a) Either
      AllowExcessFPPrecision option (-enable-excess-fp-precision for llc)
        OR
      UnsafeFPMath option (-enable-unsafe-fp-math)
    are set, and
(b) TargetLoweringInfo::isFMAFasterThanMulAndAdd(VT) is true for the type of
    the FADD/FSUB, and
(c) The FMUL only has one user (the FADD/FSUB).

If your target has fast FMA instructions you can make use of these combines by
overriding TargetLoweringInfo::isFMAFasterThanMulAndAdd(VT) to return true for
types supported by your FMA instruction, and adding patterns to match ISD::FMA
to your FMA instructions.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158757 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-19 22:51:23 +00:00

55 lines
1.7 KiB
LLVM

; RUN: llc < %s -march=ppc32 -enable-excess-fp-precision | \
; RUN: egrep {fn?madd|fn?msub} | count 8
define double @test_FMADD1(double %A, double %B, double %C) {
%D = fmul double %A, %B ; <double> [#uses=1]
%E = fadd double %D, %C ; <double> [#uses=1]
ret double %E
}
define double @test_FMADD2(double %A, double %B, double %C) {
%D = fmul double %A, %B ; <double> [#uses=1]
%E = fadd double %D, %C ; <double> [#uses=1]
ret double %E
}
define double @test_FMSUB(double %A, double %B, double %C) {
%D = fmul double %A, %B ; <double> [#uses=1]
%E = fsub double %D, %C ; <double> [#uses=1]
ret double %E
}
define double @test_FNMADD1(double %A, double %B, double %C) {
%D = fmul double %A, %B ; <double> [#uses=1]
%E = fadd double %D, %C ; <double> [#uses=1]
%F = fsub double -0.000000e+00, %E ; <double> [#uses=1]
ret double %F
}
define double @test_FNMADD2(double %A, double %B, double %C) {
%D = fmul double %A, %B ; <double> [#uses=1]
%E = fadd double %C, %D ; <double> [#uses=1]
%F = fsub double -0.000000e+00, %E ; <double> [#uses=1]
ret double %F
}
define double @test_FNMSUB1(double %A, double %B, double %C) {
%D = fmul double %A, %B ; <double> [#uses=1]
%E = fsub double %C, %D ; <double> [#uses=1]
ret double %E
}
define double @test_FNMSUB2(double %A, double %B, double %C) {
%D = fmul double %A, %B ; <double> [#uses=1]
%E = fsub double %D, %C ; <double> [#uses=1]
%F = fsub double -0.000000e+00, %E ; <double> [#uses=1]
ret double %F
}
define float @test_FNMSUBS(float %A, float %B, float %C) {
%D = fmul float %A, %B ; <float> [#uses=1]
%E = fsub float %D, %C ; <float> [#uses=1]
%F = fsub float -0.000000e+00, %E ; <float> [#uses=1]
ret float %F
}