An inline asm with multiple output operands is represented as a
parallel set in which the SET_SRCs are the same (shared) ASM_OPERANDS.
insn_propgation didn't account for this, and instead propagated
into each ASM_OPERANDS individually. This meant that it could
apply a substitution X->Y to Y itself, which (a) could create
circularity and (b) would be semantically wrong in any case,
since Y might use a different value of X.
This patch checks explicitly for parallels involving ASM_OPERANDS,
just like combine does.
Tested on aarch64-linux-gnu & x86_64-linux-gnu. OK to install?
Richard
gcc/
* recog.cc (insn_propagation::apply_to_pattern_1): Handle shared
ASM_OPERANDS.
---
gcc/recog.cc | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/gcc/recog.cc b/gcc/recog.cc
index e12b4c9500e..3bd2d73c259 100644
--- a/gcc/recog.cc
+++ b/gcc/recog.cc
@@ -1339,13 +1339,26 @@ insn_propagation::apply_to_pattern_1 (rtx *loc)
&& apply_to_pattern_1 (&COND_EXEC_CODE (body)));
case PARALLEL:
- {
- int last = XVECLEN (body, 0) - 1;
- for (int i = 0; i < last; ++i)
- if (!apply_to_pattern_1 (&XVECEXP (body, 0, i)))
- return false;
- return apply_to_pattern_1 (&XVECEXP (body, 0, last));
- }
+ for (int i = 0; i < XVECLEN (body, 0); ++i)
+ {
+ rtx *subloc = &XVECEXP (body, 0, i);
+ if (GET_CODE (*subloc) == SET)
+ {
+ if (!apply_to_lvalue_1 (SET_DEST (*subloc)))
+ return false;
+ /* ASM_OPERANDS are shared between SETs in the same PARALLEL.
+ Only process them on the first iteration. */
+ if ((i == 0 || GET_CODE (SET_SRC (*subloc)) != ASM_OPERANDS)
+ && !apply_to_rvalue_1 (&SET_SRC (*subloc)))
+ return false;
+ }
+ else
+ {
+ if (!apply_to_pattern_1 (subloc))
+ return false;
+ }
+ }
+ return true;
case ASM_OPERANDS:
for (int i = 0, len = ASM_OPERANDS_INPUT_LENGTH (body); i < len; ++i)
--
2.25.1
