llvmpipe: convert double to long long instead of unsigned long long

round(val*dscale) produces a double result, as val and dscale are double.
However, LLVMConstInt receives unsigned long long, so there is an
implicit conversion from double to unsigned long long.
This is an undefined behavior. Therefore, we need to first explicitly
convert the round result to long long, and then let the compiler handle
conversion from that to unsigned long long.

This bug manifests itself in POWER, where all IMM values of -1 are being
converted to 0 implicitly, causing a wrong LLVM IR output.

Signed-off-by: Oded Gabbay <[email protected]>
CC: "10.6 11.0" <[email protected]>
Reviewed-by: Tom Stellard <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_const.c b/src/gallium/auxiliary/gallivm/lp_bld_const.c
index 0f5a8f8e851..9cd7c5553cf 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_const.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_const.c
@@ -311,7 +311,7 @@ lp_build_const_elem(struct gallivm_state *gallivm,
    else {
       double dscale = lp_const_scale(type);
 
-      elem = LLVMConstInt(elem_type, round(val*dscale), 0);
+      elem = LLVMConstInt(elem_type, (long long) round(val*dscale), 0);
    }
 
    return elem;