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authornbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2013-10-17 11:57:44 +0000
committernbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2013-10-17 11:57:44 +0000
commitf93f3670b00995404330c32e5d0589da86f0bd57 (patch)
tree1a71b9cc29690c22852877f0d714f0184ab520ff /toolchain/gcc
parent36c38583ede8058c6d840b0ee39c25d73873be83 (diff)
gcc 4.8-linaro: backport an upstream fix to fix asm goto miscompilation
Signed-off-by: Felix Fietkau <nbd@openwrt.org> git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38435 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'toolchain/gcc')
-rw-r--r--toolchain/gcc/patches/4.8-linaro/020-fix_pr58670.patch167
1 files changed, 167 insertions, 0 deletions
diff --git a/toolchain/gcc/patches/4.8-linaro/020-fix_pr58670.patch b/toolchain/gcc/patches/4.8-linaro/020-fix_pr58670.patch
new file mode 100644
index 0000000000..8a4ae1b76e
--- /dev/null
+++ b/toolchain/gcc/patches/4.8-linaro/020-fix_pr58670.patch
@@ -0,0 +1,167 @@
+--- a/gcc/cfgrtl.c
++++ b/gcc/cfgrtl.c
+@@ -1784,10 +1784,18 @@ commit_one_edge_insertion (edge e)
+ }
+
+ /* If the source has one successor and the edge is not abnormal,
+- insert there. Except for the entry block. */
++ insert there. Except for the entry block.
++ Don't do this if the predecessor ends in a jump other than
++ unconditional simple jump. E.g. for asm goto that points all
++ its labels at the fallthru basic block, we can't insert instructions
++ before the asm goto, as the asm goto can have various of side effects,
++ and can't emit instructions after the asm goto, as it must end
++ the basic block. */
+ else if ((e->flags & EDGE_ABNORMAL) == 0
+ && single_succ_p (e->src)
+- && e->src != ENTRY_BLOCK_PTR)
++ && e->src != ENTRY_BLOCK_PTR
++ && (!JUMP_P (BB_END (e->src))
++ || simplejump_p (BB_END (e->src))))
+ {
+ bb = e->src;
+
+--- a/gcc/stmt.c
++++ b/gcc/stmt.c
+@@ -613,6 +613,9 @@ tree_conflicts_with_clobbers_p (tree t,
+ CLOBBERS is a list of STRING_CST nodes each naming a hard register
+ that is clobbered by this insn.
+
++ LABELS is a list of labels, and if LABELS is non-NULL, FALLTHRU_BB
++ should be the fallthru basic block of the asm goto.
++
+ Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
+ Some elements of OUTPUTS may be replaced with trees representing temporary
+ values. The caller should copy those temporary values to the originally
+@@ -622,7 +625,8 @@ tree_conflicts_with_clobbers_p (tree t,
+
+ static void
+ expand_asm_operands (tree string, tree outputs, tree inputs,
+- tree clobbers, tree labels, int vol, location_t locus)
++ tree clobbers, tree labels, basic_block fallthru_bb,
++ int vol, location_t locus)
+ {
+ rtvec argvec, constraintvec, labelvec;
+ rtx body;
+@@ -643,6 +647,7 @@ expand_asm_operands (tree string, tree o
+ enum machine_mode *inout_mode = XALLOCAVEC (enum machine_mode, noutputs);
+ const char **constraints = XALLOCAVEC (const char *, noutputs + ninputs);
+ int old_generating_concat_p = generating_concat_p;
++ rtx fallthru_label = NULL_RTX;
+
+ /* An ASM with no outputs needs to be treated as volatile, for now. */
+ if (noutputs == 0)
+@@ -942,8 +947,24 @@ expand_asm_operands (tree string, tree o
+
+ /* Copy labels to the vector. */
+ for (i = 0, tail = labels; i < nlabels; ++i, tail = TREE_CHAIN (tail))
+- ASM_OPERANDS_LABEL (body, i)
+- = gen_rtx_LABEL_REF (Pmode, label_rtx (TREE_VALUE (tail)));
++ {
++ rtx r;
++ /* If asm goto has any labels in the fallthru basic block, use
++ a label that we emit immediately after the asm goto. Expansion
++ may insert further instructions into the same basic block after
++ asm goto and if we don't do this, insertion of instructions on
++ the fallthru edge might misbehave. See PR58670. */
++ if (fallthru_bb
++ && label_to_block_fn (cfun, TREE_VALUE (tail)) == fallthru_bb)
++ {
++ if (fallthru_label == NULL_RTX)
++ fallthru_label = gen_label_rtx ();
++ r = fallthru_label;
++ }
++ else
++ r = label_rtx (TREE_VALUE (tail));
++ ASM_OPERANDS_LABEL (body, i) = gen_rtx_LABEL_REF (Pmode, r);
++ }
+
+ generating_concat_p = old_generating_concat_p;
+
+@@ -1067,6 +1088,9 @@ expand_asm_operands (tree string, tree o
+ emit_insn (body);
+ }
+
++ if (fallthru_label)
++ emit_label (fallthru_label);
++
+ /* For any outputs that needed reloading into registers, spill them
+ back to where they belong. */
+ for (i = 0; i < noutputs; ++i)
+@@ -1087,6 +1111,7 @@ expand_asm_stmt (gimple stmt)
+ const char *s;
+ tree str, out, in, cl, labels;
+ location_t locus = gimple_location (stmt);
++ basic_block fallthru_bb = NULL;
+
+ /* Meh... convert the gimple asm operands into real tree lists.
+ Eventually we should make all routines work on the vectors instead
+@@ -1122,6 +1147,9 @@ expand_asm_stmt (gimple stmt)
+ n = gimple_asm_nlabels (stmt);
+ if (n > 0)
+ {
++ edge fallthru = find_fallthru_edge (gimple_bb (stmt)->succs);
++ if (fallthru)
++ fallthru_bb = fallthru->dest;
+ t = labels = gimple_asm_label_op (stmt, 0);
+ for (i = 1; i < n; i++)
+ t = TREE_CHAIN (t) = gimple_asm_label_op (stmt, i);
+@@ -1147,7 +1175,7 @@ expand_asm_stmt (gimple stmt)
+
+ /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
+ OUTPUTS some trees for where the values were actually stored. */
+- expand_asm_operands (str, outputs, in, cl, labels,
++ expand_asm_operands (str, outputs, in, cl, labels, fallthru_bb,
+ gimple_asm_volatile_p (stmt), locus);
+
+ /* Copy all the intermediate outputs into the specified outputs. */
+--- /dev/null
++++ b/gcc/testsuite/gcc.dg/torture/pr58670.c
+@@ -0,0 +1,47 @@
++/* PR middle-end/58670 */
++/* { dg-do run { target i?86-*-* x86_64-*-* } } */
++
++#if defined (__i386__) || defined (__x86_64__)
++#define ASM_STR "bts $1, %0; jc %l[lab]"
++#endif
++
++__attribute__((noinline, noclone)) int
++foo (int a, int b)
++{
++ if (a)
++ return -3;
++#ifdef ASM_STR
++ asm volatile goto (ASM_STR : : "m" (b) : "memory" : lab);
++ return 0;
++lab:
++#endif
++ return 0;
++}
++
++int
++bar (int a, int b)
++{
++ if (a)
++ return -3;
++#ifdef ASM_STR
++ asm volatile goto (ASM_STR : : "m" (b) : "memory" : lab);
++ return 0;
++lab:
++#endif
++ return 0;
++}
++
++int
++main ()
++{
++ if (foo (1, 0) != -3
++ || foo (0, 3) != 0
++ || foo (1, 0) != -3
++ || foo (0, 0) != 0
++ || bar (1, 0) != -3
++ || bar (0, 3) != 0
++ || bar (1, 0) != -3
++ || bar (0, 0) != 0)
++ __builtin_abort ();
++ return 0;
++}