From 6dda86084439af4f5315a5c3aaee732a610e3551 Mon Sep 17 00:00:00 2001 From: Jeff Law Date: Sat, 30 May 2020 21:53:28 -0600 Subject: [PATCH] Disable brabc/brabs patterns as their length computation is horribly broken and leads to incorrect code generation. * config/h8300/jumpcall.md (brabs, brabc): Disable patterns. --- gcc/config/h8300/jumpcall.md | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/gcc/config/h8300/jumpcall.md b/gcc/config/h8300/jumpcall.md index 7208fb6d86b..3917cf18920 100644 --- a/gcc/config/h8300/jumpcall.md +++ b/gcc/config/h8300/jumpcall.md @@ -77,6 +77,16 @@ [(set_attr "type" "branch") (set_attr "cc" "none")]) +;; The brabc/brabs patterns have been disabled because their length computation +;; is horribly broken. When we call out to a function via a SYMBOL_REF we get +;; bogus default and minimum lengths. The trick used by the PA port seems to +;; fix the minimum, but not the default length. The broken lengths can lead +;; to bogusly using a short jump when a long jump was needed and thus +;; incorrect code. +;; +;; Given the restricted addressing modes for operand 1, we could probably just +;; open-code the necessary length computation in the two affected patterns +;; rather than using a function call. I think that would fix this problem. (define_insn "*brabc" [(set (pc) (if_then_else (eq (zero_extract (match_operand:QI 1 "bit_memory_operand" "WU") @@ -85,7 +95,7 @@ (const_int 0)) (label_ref (match_operand 0 "" "")) (pc)))] - "TARGET_H8300SX" + "0 && TARGET_H8300SX" { switch (get_attr_length (insn) - h8300_insn_length_from_table (insn, operands)) @@ -110,7 +120,7 @@ (const_int 0)) (label_ref (match_operand 0 "" "")) (pc)))] - "TARGET_H8300SX" + "0 && TARGET_H8300SX" { switch (get_attr_length (insn) - h8300_insn_length_from_table (insn, operands)) -- 2.30.2