[compiler-rt][XRay] Stash xmm registers in the trampolines

We now stash and restore the xmm registers in the trampolines so that
log handlers don't need to worry about clobbering these registers.

In response to comments in D21612.

Reviewers: rSerge, eugenis, echristo, rnk

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23051

llvm-svn: 277683

diff --git a/compiler-rt/lib/xray/xray_trampoline_x86.S b/compiler-rt/lib/xray/xray_trampoline_x86.S
index 8b8a108..8580396 100644 (file)
--- a/compiler-rt/lib/xray/xray_trampoline_x86.S
+++ b/compiler-rt/lib/xray/xray_trampoline_x86.S
@@ -24,7 +24,15 @@ __xray_FunctionEntry:
   // Save caller provided registers before doing any actual work.
        pushq %rbp
        .cfi_def_cfa_offset 16
-       subq $72, %rsp
+       subq $200, %rsp
+       movupd  %xmm0, 184(%rsp)
+       movupd  %xmm1, 168(%rsp)
+       movupd  %xmm2, 152(%rsp)
+       movupd  %xmm3, 136(%rsp)
+       movupd  %xmm4, 120(%rsp)
+       movupd  %xmm5, 104(%rsp)
+       movupd  %xmm6, 88(%rsp)
+       movupd  %xmm7, 72(%rsp)
        movq    %rdi, 64(%rsp)
        movq  %rax, 56(%rsp)
        movq  %rdx, 48(%rsp)
@@ -45,6 +53,14 @@ __xray_FunctionEntry:
        callq   *%rax
 .Ltmp0:
   // restore the registers
+       movupd  184(%rsp), %xmm0
+       movupd  168(%rsp), %xmm1
+       movupd  152(%rsp), %xmm2
+       movupd  136(%rsp), %xmm3
+       movupd  120(%rsp), %xmm4
+       movupd  104(%rsp), %xmm5
+       movupd  88(%rsp) , %xmm6
+       movupd  72(%rsp) , %xmm7
        movq    64(%rsp), %rdi
        movq  56(%rsp), %rax
        movq  48(%rsp), %rdx
@@ -52,7 +68,7 @@ __xray_FunctionEntry:
        movq    32(%rsp), %rcx
        movq    24(%rsp), %r8
        movq    16(%rsp), %r9
-       addq    $72, %rsp
+       addq    $200, %rsp
        popq    %rbp
        retq
 .Ltmp1:
@@ -67,11 +83,12 @@ __xray_FunctionExit:
        // Save the important registers first. Since we're assuming that this
        // function is only jumped into, we only preserve the registers for
        // returning.
-       // FIXME: Figure out whether this is sufficient.
        pushq   %rbp
        .cfi_def_cfa_offset 16
-       subq    $24, %rsp
+       subq    $56, %rsp
        .cfi_def_cfa_offset 32
+       movupd  %xmm0, 40(%rsp)
+       movupd  %xmm1, 24(%rsp)
        movq    %rax, 16(%rsp)
        movq    %rdx, 8(%rsp)
        movq    _ZN6__xray19XRayPatchedFunctionE(%rip), %rax
@@ -83,9 +100,11 @@ __xray_FunctionExit:
        callq   *%rax
 .Ltmp2:
   // Restore the important registers.
+       movupd  40(%rsp), %xmm0
+       movupd  24(%rsp), %xmm1
        movq    16(%rsp), %rax
        movq    8(%rsp), %rdx
-       addq    $24, %rsp
+       addq    $56, %rsp
        popq    %rbp
        retq
 .Ltmp3: