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1;Check 5.5 Parameter Passing --> Stage C --> C.4 statement, when NSAA is not2;equal to SP.3;4; Our purpose: make NSAA != SP, and only after start to use GPRs. 5;6;Co-Processor register candidates may be either in VFP or in stack, so after7;all VFP are allocated, stack is used. We can use stack without GPR allocation8;in that case, passing 9 f64 params, for example.9;First eight params goes to d0-d7, ninth one goes to the stack.10;Now, as 10th parameter, we pass i32, and it must go to R0.11;12;5.5 Parameter Passing, Stage C:13;14;C.2.cp If the argument is a CPRC then any co-processor registers in that class15;that are unallocated are marked as unavailable. The NSAA is adjusted upwards16;until it is correctly aligned for the argument and the argument is copied to17;the memory at the adjusted NSAA. The NSAA is further incremented by the size18;of the argument. The argument has now been allocated.19;...20;C.4 If the size in words of the argument is not more than r4 minus NCRN, the21;argument is copied into core registers, starting at the NCRN. The NCRN is22;incremented by the number of registers used. Successive registers hold the23;parts of the argument they would hold if its value were loaded into those24;registers from memory using an LDM instruction. The argument has now been25;allocated.26;27;What is actually checked here:28;Here we check that i32 param goes to r0.29;30;Current test-case was produced with command:31;arm-linux-gnueabihf-clang -mcpu=cortex-a9 params-to-GPR.c -S -O1 -emit-llvm32;33;// params-to-GRP.c:34;35;void fooUseI32(unsigned);36;37;void foo(long double p0,38; long double p1,39; long double p2,40; long double p3,41; long double p4,42; long double p5,43; long double p6,44; long double p7,45; long double p8,46; unsigned p9) {47; fooUseI32(p9);48;}49;50;void doFoo() {51; foo( 1,2,3,4,5,6,7,8,9, 43 );52;}53 54;RUN: llc -mtriple=thumbv7-linux-gnueabihf -float-abi=hard < %s | FileCheck %s55;56;CHECK-LABEL: foo:57;CHECK-NOT: mov r058;CHECK-NOT: ldr r059;CHECK: bl fooUseI3260;CHECK-LABEL: doFoo:61;CHECK: movs r0, #4362;CHECK: bl foo63 64define void @foo(double %p0, ; --> D065 double %p1, ; --> D166 double %p2, ; --> D267 double %p3, ; --> D368 double %p4, ; --> D469 double %p5, ; --> D570 double %p6, ; --> D671 double %p7, ; --> D772 double %p8, ; --> Stack73 i32 %p9) #0 { ; --> R0, not Stack+874entry:75 call void @fooUseI32(i32 %p9)76 ret void77}78 79declare void @fooUseI32(i32)80 81define void @doFoo() {82entry:83 tail call void @foo(double 23.0, ; --> D084 double 23.1, ; --> D185 double 23.2, ; --> D286 double 23.3, ; --> D387 double 23.4, ; --> D488 double 23.5, ; --> D589 double 23.6, ; --> D690 double 23.7, ; --> D791 double 23.8, ; --> Stack92 i32 43) ; --> R0, not Stack+893 ret void94}95 96