llvm-6502/test/CodeGen/ARM/2013-04-16-AAPCS-C4-vs-VFP.ll
Stepan Dyatkovskiy 78e3c90419 Fix for 5.5 Parameter Passing --> Stage C:
-- C.4 and C.5 statements, when NSAA is not equal to SP.
 -- C.1.cp statement for VA functions. Note: There are no VFP CPRCs in a
    variadic procedure.

Before this patch "NSAA != 0" means "don't use GPRs anymore ". But there are
some exceptions in AAPCS.
1. For non VA function: allocate all VFP regs for CPRC. When all VFPs are allocated
   CPRCs would be sent to stack, while non CPRCs may be still allocated in GRPs.
2. Check that for VA functions all params uses GPRs and then stack.
   No exceptions, no CPRCs here.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180011 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 13:06:52 +00:00

96 lines
2.9 KiB
LLVM

;Check 5.5 Parameter Passing --> Stage C --> C.4 statement, when NSAA is not
;equal to SP.
;
; Our purpose: make NSAA != SP, and only after start to use GPRs.
;
;Co-Processor register candidates may be either in VFP or in stack, so after
;all VFP are allocated, stack is used. We can use stack without GPR allocation
;in that case, passing 9 f64 params, for example.
;First eight params goes to d0-d7, ninth one goes to the stack.
;Now, as 10th parameter, we pass i32, and it must go to R0.
;
;5.5 Parameter Passing, Stage C:
;
;C.2.cp If the argument is a CPRC then any co-processor registers in that class
;that are unallocated are marked as unavailable. The NSAA is adjusted upwards
;until it is correctly aligned for the argument and the argument is copied to
;the memory at the adjusted NSAA. The NSAA is further incremented by the size
;of the argument. The argument has now been allocated.
;...
;C.4 If the size in words of the argument is not more than r4 minus NCRN, the
;argument is copied into core registers, starting at the NCRN. The NCRN is
;incremented by the number of registers used. Successive registers hold the
;parts of the argument they would hold if its value were loaded into those
;registers from memory using an LDM instruction. The argument has now been
;allocated.
;
;What is actually checked here:
;Here we check that i32 param goes to r0.
;
;Current test-case was produced with command:
;arm-linux-gnueabihf-clang -mcpu=cortex-a9 params-to-GPR.c -S -O1 -emit-llvm
;
;// params-to-GRP.c:
;
;void fooUseI32(unsigned);
;
;void foo(long double p0,
; long double p1,
; long double p2,
; long double p3,
; long double p4,
; long double p5,
; long double p6,
; long double p7,
; long double p8,
; unsigned p9) {
; fooUseI32(p9);
;}
;
;void doFoo() {
; foo( 1,2,3,4,5,6,7,8,9, 43 );
;}
;RUN: llc -mtriple=thumbv7-linux-gnueabihf -float-abi=hard < %s | FileCheck %s
;
;CHECK: foo:
;CHECK-NOT: mov r0
;CHECK-NOT: ldr r0
;CHECK: bl fooUseI32
;CHECK: doFoo:
;CHECK: movs r0, #43
;CHECK: bl foo
define void @foo(double %p0, ; --> D0
double %p1, ; --> D1
double %p2, ; --> D2
double %p3, ; --> D3
double %p4, ; --> D4
double %p5, ; --> D5
double %p6, ; --> D6
double %p7, ; --> D7
double %p8, ; --> Stack
i32 %p9) #0 { ; --> R0, not Stack+8
entry:
tail call void @fooUseI32(i32 %p9)
ret void
}
declare void @fooUseI32(i32)
define void @doFoo() {
entry:
tail call void @foo(double 23.0, ; --> D0
double 23.1, ; --> D1
double 23.2, ; --> D2
double 23.3, ; --> D3
double 23.4, ; --> D4
double 23.5, ; --> D5
double 23.6, ; --> D6
double 23.7, ; --> D7
double 23.8, ; --> Stack
i32 43) ; --> R0, not Stack+8
ret void
}