This patch addresses PR13947.

For function calls on the 64-bit PowerPC SVR4 target, each parameter
is mapped to as many doublewords in the parameter save area as
necessary to hold the parameter.  The first 13 non-varargs
floating-point values are passed in registers; any additional
floating-point parameters are passed in the parameter save area.  A
single-precision floating-point parameter (32 bits) must be mapped to
the second (rightmost, low-order) word of its assigned doubleword
slot.

Currently LLVM violates this ABI requirement by mapping such a
parameter to the first (leftmost, high-order) word of its assigned
doubleword slot.  This is internally self-consistent but will not
interoperate correctly with libraries compiled with an ABI-compliant
compiler.

This patch corrects the problem by adjusting the parameter addressing
on both sides of the calling convention.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165714 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Schmidt 2012-10-11 15:38:20 +00:00
parent a54b2dfb0a
commit a867f37897
2 changed files with 105 additions and 0 deletions

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@ -2142,6 +2142,7 @@ PPCTargetLowering::LowerFormalArguments_64SVR4(
++FPR_idx;
} else {
needsLoad = true;
ArgSize = PtrByteSize;
}
ArgOffset += 8;
@ -3786,6 +3787,13 @@ PPCTargetLowering::LowerCall_Darwin_Or_64SVR4(SDValue Chain, SDValue Callee,
++GPR_idx;
}
} else {
// Single-precision floating-point values are mapped to the
// second (rightmost) word of the stack doubleword.
if (Arg.getValueType() == MVT::f32 && isPPC64 && isSVR4ABI) {
SDValue ConstFour = DAG.getConstant(4, PtrOff.getValueType());
PtrOff = DAG.getNode(ISD::ADD, dl, PtrVT, PtrOff, ConstFour);
}
LowerMemOpCallTo(DAG, MF, Chain, Arg, PtrOff, SPDiff, ArgOffset,
isPPC64, isTailCall, false, MemOpChains,
TailCallArguments, dl);

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@ -0,0 +1,97 @@
; RUN: llc -O0 -mtriple=powerpc64-unknown-linux-gnu < %s | FileCheck %s
; This verifies that single-precision floating point values that can't
; be passed in registers are stored in the rightmost word of the parameter
; save area slot. There are 13 architected floating-point registers, so
; the 14th is passed in storage. The address of the 14th argument is
; 48 (fixed size of the linkage area) + 13 * 8 (first 13 args) + 4
; (offset to second word) = 156.
define float @bar(float %a, float %b, float %c, float %d, float %e, float %f, float %g, float %h, float %i, float %j, float %k, float %l, float %m, float %n) nounwind {
entry:
%a.addr = alloca float, align 4
%b.addr = alloca float, align 4
%c.addr = alloca float, align 4
%d.addr = alloca float, align 4
%e.addr = alloca float, align 4
%f.addr = alloca float, align 4
%g.addr = alloca float, align 4
%h.addr = alloca float, align 4
%i.addr = alloca float, align 4
%j.addr = alloca float, align 4
%k.addr = alloca float, align 4
%l.addr = alloca float, align 4
%m.addr = alloca float, align 4
%n.addr = alloca float, align 4
store float %a, float* %a.addr, align 4
store float %b, float* %b.addr, align 4
store float %c, float* %c.addr, align 4
store float %d, float* %d.addr, align 4
store float %e, float* %e.addr, align 4
store float %f, float* %f.addr, align 4
store float %g, float* %g.addr, align 4
store float %h, float* %h.addr, align 4
store float %i, float* %i.addr, align 4
store float %j, float* %j.addr, align 4
store float %k, float* %k.addr, align 4
store float %l, float* %l.addr, align 4
store float %m, float* %m.addr, align 4
store float %n, float* %n.addr, align 4
%0 = load float* %n.addr, align 4
ret float %0
}
; CHECK: lfs {{[0-9]+}}, 156(1)
define float @foo() nounwind {
entry:
%a = alloca float, align 4
%b = alloca float, align 4
%c = alloca float, align 4
%d = alloca float, align 4
%e = alloca float, align 4
%f = alloca float, align 4
%g = alloca float, align 4
%h = alloca float, align 4
%i = alloca float, align 4
%j = alloca float, align 4
%k = alloca float, align 4
%l = alloca float, align 4
%m = alloca float, align 4
%n = alloca float, align 4
store float 1.000000e+00, float* %a, align 4
store float 2.000000e+00, float* %b, align 4
store float 3.000000e+00, float* %c, align 4
store float 4.000000e+00, float* %d, align 4
store float 5.000000e+00, float* %e, align 4
store float 6.000000e+00, float* %f, align 4
store float 7.000000e+00, float* %g, align 4
store float 8.000000e+00, float* %h, align 4
store float 9.000000e+00, float* %i, align 4
store float 1.000000e+01, float* %j, align 4
store float 1.100000e+01, float* %k, align 4
store float 1.200000e+01, float* %l, align 4
store float 1.300000e+01, float* %m, align 4
store float 1.400000e+01, float* %n, align 4
%0 = load float* %a, align 4
%1 = load float* %b, align 4
%2 = load float* %c, align 4
%3 = load float* %d, align 4
%4 = load float* %e, align 4
%5 = load float* %f, align 4
%6 = load float* %g, align 4
%7 = load float* %h, align 4
%8 = load float* %i, align 4
%9 = load float* %j, align 4
%10 = load float* %k, align 4
%11 = load float* %l, align 4
%12 = load float* %m, align 4
%13 = load float* %n, align 4
%call = call float @bar(float %0, float %1, float %2, float %3, float %4, float %5, float %6, float %7, float %8, float %9, float %10, float %11, float %12, float %13)
ret float %call
}
; Note that stw is used instead of stfs because the value is a simple
; constant that can be created with a load-immediate in a GPR.
; CHECK: stw {{[0-9]+}}, 156(1)