[ARM] Enable DP copy, load and store instructions for FPv4-SP

The FPv4-SP floating-point unit is generally referred to as
single-precision only, but it does have double-precision registers and
load, store and GPR<->DPR move instructions which operate on them.
This patch enables the use of these registers, the main advantage of
which is that we now comply with the AAPCS-VFP calling convention.
This partially reverts r209650, which added some AAPCS-VFP support,
but did not handle return values or alignment of double arguments in
registers.

This patch also adds tests for Thumb2 code generation for
floating-point instructions and intrinsics, which previously only
existed for ARM.

llvm-svn: 216172

1 files changed, 50 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/Thumb2/aapcs.ll b/llvm/test/CodeGen/Thumb2/aapcs.ll
new file mode 100644
index 00000000000..21af8c119b0
--- /dev/null
+++ b/llvm/test/CodeGen/Thumb2/aapcs.ll
@@ -0,0 +1,50 @@
+; RUN: llc < %s -mtriple=thumbv7-none-eabi   -mcpu=cortex-m4 -mattr=-vfp2             | FileCheck %s -check-prefix=CHECK -check-prefix=SOFT
+; RUN: llc < %s -mtriple=thumbv7-none-eabihf -mcpu=cortex-m4 -mattr=+vfp4,+fp-only-sp | FileCheck %s -check-prefix=CHECK -check-prefix=HARD -check-prefix=SP
+; RUN: llc < %s -mtriple=thumbv7-none-eabihf -mcpu=cortex-a8 -mattr=+vfp3             | FileCheck %s -check-prefix=CHECK -check-prefix=HARD -check-prefix=DP
+
+define float @float_in_reg(float %a, float %b) {
+entry:
+; CHECK-LABEL: float_in_reg:
+; SOFT: mov r0, r1
+; HARD: vmov.f32  s0, s1
+; CHECK-NEXT: bx lr
+  ret float %b
+}
+
+define double @double_in_reg(double %a, double %b) {
+entry:
+; CHECK-LABEL: double_in_reg:
+; SOFT: mov r0, r2
+; SOFT: mov r1, r3
+; SP: vmov.f32  s0, s2
+; SP: vmov.f32  s1, s3
+; DP: vmov.f64  d0, d1
+; CHECK-NEXT: bx lr
+  ret double %b
+}
+
+define float @float_on_stack(double %a, double %b, double %c, double %d, double %e, double %f, double %g, double %h, float %i) {
+; CHECK-LABEL: float_on_stack:
+; SOFT: ldr r0, [sp, #48]
+; HARD: vldr s0, [sp]
+; CHECK-NEXT: bx lr
+  ret float %i
+}
+
+define double @double_on_stack(double %a, double %b, double %c, double %d, double %e, double %f, double %g, double %h, double %i) {
+; CHECK-LABEL: double_on_stack:
+; SOFT: ldr r0, [sp, #48]
+; SOFT: ldr r1, [sp, #52]
+; HARD: vldr d0, [sp]
+; CHECK-NEXT: bx lr
+  ret double %i
+}
+
+define double @double_not_split(double %a, double %b, double %c, double %d, double %e, double %f, double %g, float %h, double %i) {
+; CHECK-LABEL: double_not_split:
+; SOFT: ldr r0, [sp, #48]
+; SOFT: ldr r1, [sp, #52]
+; HARD: vldr d0, [sp]
+; CHECK-NEXT: bx lr
+  ret double %i
+}