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* [Qemu-devel] [PATCH 088/111] m68k: allows bfins to manage correctly width = 32
@ 2011-08-17 20:52 Bryce Lanham
  0 siblings, 0 replies; only message in thread
From: Bryce Lanham @ 2011-08-17 20:52 UTC (permalink / raw)
  To: qemu-devel; +Cc: Laurent Vivier

From: Laurent Vivier <laurent@vivier.eu>

tcg_gen_shl_i32() doesn't manage a shift of 32.

As 32 >= width >= 1, we use two tcg_gen_shl_i32():
tcg_gen_shl_i32(1) and tcg_gen_shl_i32(width - 1)

seen with gcc testsuite,
gcc-4.1.2/gcc/testsuite/gcc.c-torture/execute/991118-1.c

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 target-m68k/translate.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/target-m68k/translate.c b/target-m68k/translate.c
index 96ea93f..52df274 100644
--- a/target-m68k/translate.c
+++ b/target-m68k/translate.c
@@ -3215,7 +3215,11 @@ static void gen_bitfield_ins(TCGv offset, TCGv width, TCGv src,
 
     /* tmp = (1u << width) - 1; */
 
-    tcg_gen_shl_i32(tmp, tcg_const_i32(1), width);
+    /* width is between 1 and 32
+     * tcg_gen_shl_i32() cannot manage value 32
+     */
+    tcg_gen_subi_i32(tmp, width, 1);
+    tcg_gen_shl_i32(tmp, tcg_const_i32(2), tmp);
     tcg_gen_subi_i32(tmp, tmp, 1);
 
     /* tmp = tmp & src; */
-- 
1.7.2.3

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